diff --git a/src/main/java/carpet/script/CarpetScriptHost.java b/src/main/java/carpet/script/CarpetScriptHost.java
index 3e876568..c9bf4c77 100644
--- a/src/main/java/carpet/script/CarpetScriptHost.java
+++ b/src/main/java/carpet/script/CarpetScriptHost.java
@@ -283,21 +283,7 @@ public class CarpetScriptHost extends ScriptHost
             Map<Value, Value> config = ((MapValue) ret).getMap();
             setPerPlayer(config.getOrDefault(new StringValue("scope"), new StringValue("player")).getString().equalsIgnoreCase("player"));
             persistenceRequired = config.getOrDefault(new StringValue("stay_loaded"), Value.TRUE).getBoolean();
-            // read custom arguments
-            Value arguments = config.get(StringValue.of("arguments"));
-            if (arguments != null)
-            {
-                if (!(arguments instanceof MapValue))
-                    throw new InternalExpressionException("'arguments' element in config should be a map");
-                for (Map.Entry<Value, Value> typeData : ((MapValue)arguments).getMap().entrySet())
-                {
-                    String argument = typeData.getKey().getString();
-                    Value spec = typeData.getValue();
-                    if (!(spec instanceof MapValue)) throw new InternalExpressionException("Spec for '"+argument+"' should be a map");
-                    Map<String, Value> specData = ((MapValue) spec).getMap().entrySet().stream().collect(Collectors.toMap(e -> e.getKey().getString(), Map.Entry::getValue));
-                    appArgTypes.put(argument, CommandArgument.buildFromConfig(argument, specData, this));
-                }
-            }
+
             appConfig = config;
         }
         catch (NullPointerException ignored)
@@ -323,8 +309,37 @@ public class CarpetScriptHost extends ScriptHost
         }
     }
 
+    public void readCustomArgumentTypes() throws CommandSyntaxException
+    {
+        // read custom arguments
+        Value arguments = appConfig.get(StringValue.of("arguments"));
+        if (arguments != null)
+        {
+            if (!(arguments instanceof MapValue))
+                throw CommandArgument.error("'arguments' element in config should be a map");
+            appArgTypes.clear();
+            for (Map.Entry<Value, Value> typeData : ((MapValue)arguments).getMap().entrySet())
+            {
+                String argument = typeData.getKey().getString();
+                Value spec = typeData.getValue();
+                if (!(spec instanceof MapValue)) throw CommandArgument.error("Spec for '"+argument+"' should be a map");
+                Map<String, Value> specData = ((MapValue) spec).getMap().entrySet().stream().collect(Collectors.toMap(e -> e.getKey().getString(), Map.Entry::getValue));
+                appArgTypes.put(argument, CommandArgument.buildFromConfig(argument, specData, this));
+            }
+        }
+    }
+
     public Boolean addAppCommands(Consumer<Text> notifier)
     {
+        try
+        {
+            readCustomArgumentTypes();
+        }
+        catch (CommandSyntaxException e)
+        {
+            notifier.accept(Messenger.c("Error when handling of setting up custom argument types: "+e.getMessage()));
+            return false;
+        }
         if (appConfig.get(StringValue.of("commands")) != null)
         {
             try
@@ -342,7 +357,7 @@ public class CarpetScriptHost extends ScriptHost
             catch (CommandSyntaxException cse)
             {
                 // failed
-                notifier.accept(Messenger.c("r Failed to build command system for "+getName()+" thus failed to load the app ", cse.getRawMessage()));
+                notifier.accept(Messenger.c("r Failed to build command system for "+getName()+" thus failed to load the app: ", cse.getRawMessage()));
                 return null;
             }
 
@@ -382,9 +397,11 @@ public class CarpetScriptHost extends ScriptHost
                     return (int)response.readInteger();
                 });
 
+        boolean hasTypeSupport = appConfig.getOrDefault(StringValue.of("legacy_command_type_support"), Value.FALSE).getBoolean();
+
         for (String function : globaFunctionNames(main, s ->  !s.startsWith("_")).sorted().collect(Collectors.toList()))
         {
-            if (appConfig.getOrDefault(StringValue.of("legacy_command_type_support"), Value.FALSE).getBoolean())
+            if (hasTypeSupport)
             {
                 try
                 {
diff --git a/src/main/java/carpet/script/api/Auxiliary.java b/src/main/java/carpet/script/api/Auxiliary.java
index 1428e029..73018c8e 100644
--- a/src/main/java/carpet/script/api/Auxiliary.java
+++ b/src/main/java/carpet/script/api/Auxiliary.java
@@ -338,6 +338,8 @@ public class Auxiliary {
         expression.addLazyFunction("draw_shape", -1, (c, t, lv) ->
         {
             CarpetContext cc = (CarpetContext)c;
+            ServerWorld world = cc.s.getWorld();
+            MinecraftServer server = world.getServer();
             ServerPlayerEntity player[] = {null};
             List<Pair<ShapeDispatcher.ExpiringShape, Map<String,Value>>> shapes = new ArrayList<>();
             if (lv.size() == 1) // bulk
@@ -347,14 +349,14 @@ public class Auxiliary {
                 for (Value list : ((ListValue) specLoad).getItems())
                 {
                     if (!(list instanceof ListValue))  throw new InternalExpressionException("In bulk mode - shapes need to be provided as a list of shape specs");
-                    shapes.add( ShapeDispatcher.fromFunctionArgs(cc, ((ListValue) list).getItems(), player));
+                    shapes.add( ShapeDispatcher.fromFunctionArgs(server, world, ((ListValue) list).getItems(), player));
                 }
             }
             else
             {
                 List<Value> params = new ArrayList<>();
                 for (LazyValue v : lv) params.add(v.evalValue(c));
-                shapes.add(ShapeDispatcher.fromFunctionArgs(cc, params, player));
+                shapes.add(ShapeDispatcher.fromFunctionArgs(server, world, params, player));
             }
 
             ShapeDispatcher.sendShape(
diff --git a/src/main/java/carpet/script/argument/FunctionArgument.java b/src/main/java/carpet/script/argument/FunctionArgument.java
index b942e7f7..8c52c8d5 100644
--- a/src/main/java/carpet/script/argument/FunctionArgument.java
+++ b/src/main/java/carpet/script/argument/FunctionArgument.java
@@ -4,10 +4,12 @@ import carpet.script.Context;
 import carpet.script.LazyValue;
 import carpet.script.ScriptHost;
 import carpet.script.bundled.Module;
+import carpet.script.command.CommandArgument;
 import carpet.script.exception.InternalExpressionException;
 import carpet.script.value.FunctionValue;
 import carpet.script.value.ListValue;
 import carpet.script.value.Value;
+import com.mojang.brigadier.exceptions.CommandSyntaxException;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -70,14 +72,13 @@ public class FunctionArgument<T> extends Argument
         return new FunctionArgument<>(fun, offset + 1 + argsize, lvargs);
     }
 
-    public static FunctionArgument<Value> fromCommandSpec(ScriptHost host, Value funSpec)
-    {
+    public static FunctionArgument<Value> fromCommandSpec(ScriptHost host, Value funSpec) throws CommandSyntaxException {
         FunctionValue function;
         List<Value> args = Collections.emptyList();
         if (!(funSpec instanceof ListValue))
             funSpec = ListValue.of(funSpec);
         List<Value> params = ((ListValue) funSpec).getItems();
-        if (params.isEmpty()) throw new InternalExpressionException("Function has empty spec");
+        if (params.isEmpty()) throw CommandArgument.error("Function has empty spec");
         Value first = params.get(0);
         if (first instanceof FunctionValue)
         {
@@ -86,7 +87,8 @@ public class FunctionArgument<T> extends Argument
         else
         {
             String name = first.getString();
-            function = host.getAssertFunction(host.main, name);
+            function = host.getFunction(name);
+            if (function == null) throw CommandArgument.error("Function "+name+" is not defined yet");
         }
         if (params.size() > 1) args = params.subList(1,params.size());
 
diff --git a/src/main/java/carpet/script/command/CommandArgument.java b/src/main/java/carpet/script/command/CommandArgument.java
index 6406373a..2a8f39bc 100644
--- a/src/main/java/carpet/script/command/CommandArgument.java
+++ b/src/main/java/carpet/script/command/CommandArgument.java
@@ -319,20 +319,20 @@ public abstract class CommandArgument
         return suffix;
     }
 
-    public static CommandArgument buildFromConfig(String suffix, Map<String, Value> config, CarpetScriptHost host)
+    public static CommandArgument buildFromConfig(String suffix, Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
     {
         if (!config.containsKey("type"))
-            throw new InternalExpressionException("Custom type "+suffix+" should at least specify the type");
+            throw CommandArgument.error("Custom type "+suffix+" should at least specify the type");
         String baseType = config.get("type").getString();
         if (!builtIns.containsKey(baseType))
-            throw new InternalExpressionException("Unknown base type "+baseType+" for custom type "+suffix);
+            throw CommandArgument.error("Unknown base type "+baseType+" for custom type "+suffix);
         CommandArgument variant = builtIns.get(baseType).factory().get();
         variant.suffix = suffix;
         variant.configure(config, host);
         return variant;
     }
 
-    protected void configure(Map<String, Value> config, CarpetScriptHost host)
+    protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
     {
         caseSensitive = config.getOrDefault("case_sensitive", Value.TRUE).getBoolean();
         if (config.containsKey("suggester"))
@@ -341,9 +341,9 @@ public abstract class CommandArgument
         }
         if (config.containsKey("suggest"))
         {
-            if (config.containsKey("suggester")) throw new InternalExpressionException("Attempted to provide 'suggest' list while 'suggester' is present"+" for custom type "+suffix);
+            if (config.containsKey("suggester")) throw error("Attempted to provide 'suggest' list while 'suggester' is present"+" for custom type "+suffix);
             Value suggestionValue = config.get("suggest");
-            if (!(suggestionValue instanceof ListValue)) throw new InternalExpressionException("Argument suggestions needs to be a list"+" for custom type "+suffix);
+            if (!(suggestionValue instanceof ListValue)) throw error("Argument suggestions needs to be a list"+" for custom type "+suffix);
             examples = ((ListValue) suggestionValue).getItems().stream()
                     .map(Value::getString)
                     .collect(Collectors.toSet());
@@ -442,13 +442,13 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             if (config.containsKey("options"))
             {
                 Value optionsValue = config.get("options");
-                if (!(optionsValue instanceof ListValue)) throw new InternalExpressionException("Custom string type requires options passed as a list"+" for custom type "+suffix);
+                if (!(optionsValue instanceof ListValue)) throw error("Custom string type requires options passed as a list"+" for custom type "+suffix);
                 validOptions = ((ListValue) optionsValue).getItems().stream()
                         .map(v -> caseSensitive?v.getString():(v.getString().toLowerCase(Locale.ROOT)))
                         .collect(Collectors.toSet());
@@ -508,7 +508,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             mustBeLoaded = config.getOrDefault("loaded", Value.FALSE).getBoolean();
@@ -543,7 +543,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             blockCentered = config.getOrDefault("block_centered", Value.TRUE).getBoolean();
@@ -591,7 +591,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             onlyFans = config.getOrDefault("players", Value.FALSE).getBoolean();
@@ -632,7 +632,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             single = config.getOrDefault("single", Value.FALSE).getBoolean();
@@ -673,7 +673,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             single = config.getOrDefault("single", Value.FALSE).getBoolean();
@@ -710,7 +710,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             mapRequired = !config.getOrDefault("allow_element", Value.FALSE).getBoolean();
@@ -756,13 +756,13 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             if (config.containsKey("options"))
             {
                 Value optionsValue = config.get("options");
-                if (!(optionsValue instanceof ListValue)) throw new InternalExpressionException("Custom sting type requires options passed as a list"+" for custom type "+suffix);
+                if (!(optionsValue instanceof ListValue)) throw error("Custom sting type requires options passed as a list"+" for custom type "+suffix);
                 validOptions = ((ListValue) optionsValue).getItems().stream().map(v -> new Identifier(v.getString())).collect(Collectors.toSet());
             }
         }
@@ -798,7 +798,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             if (config.containsKey("min"))
@@ -809,7 +809,7 @@ public abstract class CommandArgument
             {
                 max = NumericValue.asNumber(config.get("max"), "max").getDouble();
             }
-            if (max != null && min == null) throw new InternalExpressionException("Double types cannot be only upper-bounded"+" for custom type "+suffix);
+            if (max != null && min == null) throw error("Double types cannot be only upper-bounded"+" for custom type "+suffix);
         }
 
         @Override
@@ -849,7 +849,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             if (config.containsKey("min"))
@@ -860,7 +860,7 @@ public abstract class CommandArgument
             {
                 max = NumericValue.asNumber(config.get("max"), "max").getLong();
             }
-            if (max != null && min == null) throw new InternalExpressionException("Double types cannot be only upper-bounded"+" for custom type "+suffix);
+            if (max != null && min == null) throw error("Double types cannot be only upper-bounded"+" for custom type "+suffix);
         }
 
         @Override
@@ -939,7 +939,7 @@ public abstract class CommandArgument
         }
 
         @Override
-        protected void configure(Map<String, Value> config, CarpetScriptHost host)
+        protected void configure(Map<String, Value> config, CarpetScriptHost host) throws CommandSyntaxException
         {
             super.configure(config, host);
             if (config.containsKey("restrict"))
@@ -947,7 +947,7 @@ public abstract class CommandArgument
                 restrict = config.get("restrict").getString().toLowerCase(Locale.ROOT);
                 needsMatching = true;
                 if (!RESTRICTED_CONTAINERS.containsKey(restrict))
-                    throw new InternalExpressionException("Incorrect slot restriction "+restrict+" for custom type "+suffix);
+                    throw error("Incorrect slot restriction "+restrict+" for custom type "+suffix);
             }
         }
 
diff --git a/src/main/java/carpet/script/utils/ShapeDispatcher.java b/src/main/java/carpet/script/utils/ShapeDispatcher.java
index 1e48f591..2a8b21e7 100644
--- a/src/main/java/carpet/script/utils/ShapeDispatcher.java
+++ b/src/main/java/carpet/script/utils/ShapeDispatcher.java
@@ -31,6 +31,7 @@ import net.minecraft.nbt.NbtList;
 import net.minecraft.nbt.NbtString;
 import net.minecraft.nbt.NbtElement;
 import net.minecraft.particle.ParticleEffect;
+import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.text.LiteralText;
@@ -62,7 +63,7 @@ public class ShapeDispatcher
     private static final Map<String, ParticleEffect> particleCache = new HashMap<>();
 
     public static Pair<ExpiringShape,Map<String, Value>> fromFunctionArgs(
-            CarpetContext cc,
+            MinecraftServer server, ServerWorld world,
             List<Value> lv,
             ServerPlayerEntity[] playerRef
     )
@@ -91,18 +92,18 @@ public class ShapeDispatcher
             for (int i=2; i < lv.size(); i++) paramList.add(lv.get(i));
             params = ShapeDispatcher.parseParams(paramList);
         }
-        params.putIfAbsent("dim", new StringValue(cc.s.getWorld().getRegistryKey().getValue().toString()));
+        params.putIfAbsent("dim", new StringValue(world.getRegistryKey().getValue().toString()));
         params.putIfAbsent("duration", duration);
 
         if (params.containsKey("player"))
         {
-            ServerPlayerEntity player = EntityValue.getPlayerByValue(cc.s.getMinecraftServer(), params.get("player"));
+            ServerPlayerEntity player = EntityValue.getPlayerByValue(server, params.get("player"));
             if (player == null)
                 throw new InternalExpressionException("'player' parameter needs to represent an existing player");
             params.remove("player");
             playerRef[0] = player;
         }
-        return Pair.of(ShapeDispatcher.create(cc, shapeType, params), params);
+        return Pair.of(ShapeDispatcher.create(server, shapeType, params), params);
     }
 
     public static void sendShape(List<ServerPlayerEntity> players, List<Pair<ExpiringShape,Map<String, Value>>> shapes)
@@ -180,13 +181,13 @@ public class ShapeDispatcher
         return param;
     }
 
-    public static ExpiringShape create(CarpetContext cc, String shapeType, Map<String, Value> userParams)
+    public static ExpiringShape create(MinecraftServer server, String shapeType, Map<String, Value> userParams)
     {
         userParams.put("shape", new StringValue(shapeType));
         userParams.keySet().forEach(key -> {
             Param param = Param.of.get(key);
             if (param==null) throw new InternalExpressionException("Unknown feature for shape: "+key);
-            userParams.put(key, param.validate(userParams, cc, userParams.get(key)));
+            userParams.put(key, param.validate(userParams, server, userParams.get(key)));
         });
         Function<Map<String, Value>,ExpiringShape> factory = ExpiringShape.shapeProviders.get(shapeType);
         if (factory == null) throw new InternalExpressionException("Unknown shape: "+shapeType);
@@ -891,7 +892,7 @@ public class ShapeDispatcher
         }
 
         public abstract NbtElement toTag(Value value); //validates value, returning null if not necessary to keep it and serialize
-        public abstract Value validate(Map<String, Value> options, CarpetContext cc, Value value); // makes sure the value is proper
+        public abstract Value validate(Map<String, Value> options, MinecraftServer server, Value value); // makes sure the value is proper
         public abstract Value decode(NbtElement tag);
     }
 
@@ -910,7 +911,7 @@ public class ShapeDispatcher
             super(id);
         }
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
             return value;
         }
@@ -923,7 +924,7 @@ public class ShapeDispatcher
             super(id);
         }
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
             if (!(value instanceof FormattedTextValue))
                 value = new FormattedTextValue(new LiteralText(value.getString()));
@@ -957,7 +958,7 @@ public class ShapeDispatcher
 
 
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
             if (this.options.contains(value.getString())) return value;
             return null;
@@ -969,14 +970,14 @@ public class ShapeDispatcher
         protected DimensionParam() { super("dim"); }
 
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value) { return value; }
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value) { return value; }
     }
     public static class ShapeParam extends StringParam
     {
         protected ShapeParam() { super("shape"); }
 
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
             String shape = value.getString();
             if (!ExpiringShape.shapeProviders.containsKey(shape))
@@ -989,7 +990,7 @@ public class ShapeDispatcher
         protected NumericParam(String id) { super(id); }
 
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
             if (!(value instanceof NumericValue))
                 throw new InternalExpressionException("'" + id + "' needs to be a number");
@@ -1027,9 +1028,9 @@ public class ShapeDispatcher
     public static abstract class PositiveParam extends NumericParam
     {
         protected PositiveParam(String id) { super(id); }
-        @Override public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        @Override public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
-            Value ret = super.validate(options, cc, value);
+            Value ret = super.validate(options, server, value);
             if (((NumericValue)ret).getDouble()<=0) throw new InternalExpressionException("'"+id+"' should be positive");
             return ret;
         }
@@ -1059,9 +1060,9 @@ public class ShapeDispatcher
         public Value decode(NbtElement tag) { return new NumericValue(((NbtInt)tag).intValue()); }
         @Override
         public NbtElement toTag(Value value) { return NbtInt.of(NumericValue.asNumber(value, id).getInt()); }
-        @Override public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        @Override public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
-            Value ret = super.validate(options, cc, value);
+            Value ret = super.validate(options, server, value);
             if (((NumericValue)ret).getDouble()<0) throw new InternalExpressionException("'"+id+"' should be non-negative");
             return ret;
         }
@@ -1073,9 +1074,9 @@ public class ShapeDispatcher
         public Value decode(NbtElement tag) { return new NumericValue(((NbtFloat)tag).floatValue()); }
         @Override
         public NbtElement toTag(Value value) { return NbtFloat.of(NumericValue.asNumber(value, id).getFloat()); }
-        @Override public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        @Override public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
-            Value ret = super.validate(options, cc, value);
+            Value ret = super.validate(options, server, value);
             if (((NumericValue)ret).getDouble()<0) throw new InternalExpressionException("'"+id+"' should be non-negative");
             return ret;
         }
@@ -1093,11 +1094,11 @@ public class ShapeDispatcher
             roundsUpForBlocks = doesRoundUpForBlocks;
         }
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
-            return validate(this, options, cc, value, roundsUpForBlocks);
+            return validate(this, options, value, roundsUpForBlocks);
         }
-        public static Value validate(Param p, Map<String, Value> options, CarpetContext cc, Value value, boolean roundsUp)
+        public static Value validate(Param p, Map<String, Value> options, Value value, boolean roundsUp)
         {
             if (value instanceof BlockValue)
             {
@@ -1165,13 +1166,13 @@ public class ShapeDispatcher
             super(id);
         }
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
             if (!(value instanceof ListValue))
                 throw new InternalExpressionException(id+ " parameter should be a list");
             List<Value> points = new ArrayList<>();
             for (Value point: ((ListValue) value).getItems())
-                points.add(Vec3Param.validate(this, options, cc, point, false));
+                points.add(Vec3Param.validate(this, options, point, false));
             return ListValue.wrap(points);
         }
 
@@ -1233,10 +1234,10 @@ public class ShapeDispatcher
         }
 
         @Override
-        public Value validate(Map<String, Value> options, CarpetContext cc, Value value)
+        public Value validate(Map<String, Value> options, MinecraftServer server, Value value)
         {
             if (value instanceof EntityValue) return new NumericValue(((EntityValue) value).getEntity().getId());
-            ServerPlayerEntity player = EntityValue.getPlayerByValue(cc.s.getMinecraftServer(), value);
+            ServerPlayerEntity player = EntityValue.getPlayerByValue(server, value);
             if (player == null)
                 throw new InternalExpressionException(id+" parameter needs to represent an entity or player");
             return new NumericValue(player.getId());