Fixed bug in SetDimension method of World class, where it would crash if joining a paper server. Added error handling.

MinecraftClient/Mapping/World.cs

@@ -89,9 +89,31 @@ namespace MinecraftClient.Mapping
         /// <param name="nbt">The dimension type (NBT Tag Compound)</param>
 	public static void SetDimension(string name)
 	{
-            curDimension = dimensionList[name]; // Should not fail
+	    // Try to get the dimension using the name as is
+	    if (dimensionList.TryGetValue(name, out Dimension dimension))
+	    {
+		curDimension = dimension;
+		return; // Dimension found
 	    }
 
+	    // If not found, check if name lacks 'minecraft:' prefix and try again
+	    if (!name.StartsWith("minecraft:"))
+	    {
+		string prefixedName = "minecraft:" + name;
+		if (dimensionList.TryGetValue(prefixedName, out dimension))
+		{
+		    curDimension = dimension;
+		    return; // Dimension found with prefixed name
+		}
+	    }
+
+	    // If still not found, dimension does not exist
+	    throw new KeyNotFoundException($"Dimension '{name}' not found in dimensions dictionary.");
+	}
+
+
+
+
 
         /// <summary>
         /// Get current dimension

MinecraftClient/Protocol/Handlers/Protocol18.cs

@@ -660,6 +660,7 @@ namespace MinecraftClient.Protocol.Handlers
                                     {
                                         case >= MC_1_16_2_Version and <= MC_1_18_2_Version:
                                             World.StoreOneDimension(dimensionName, dimensionType!);
+                                            // World.SetDimension(dimensionName);
 					    World.SetDimension(dimensionName);
                                             break;
                                         default: