Fixes sidedness issues when starting up the server.

src/main/java/appeng/items/parts/PartType.java

@@ -283,7 +283,7 @@ public enum PartType
 		{
 			// Only load models if the part is enabled, otherwise we also run into class-loading issues while
 			// scanning for annotations
-			if( Platform.isClient() )
+			if( Platform.isClientInstall() )
 			{
 				this.itemModels = createItemModels( itemModel );
 			}
@@ -298,7 +298,10 @@ public enum PartType
 		}
 		else
 		{
-			this.itemModels = Collections.emptyList();
+			if( Platform.isClientInstall() )
+			{
+				this.itemModels = Collections.emptyList();
+			}
 			this.models = Collections.emptySet();
 		}
 	}

src/main/java/appeng/util/Platform.java

@@ -150,6 +150,8 @@ public class Platform
 
 	public static final int DEF_OFFSET = 16;
 
+	private static final boolean CLIENT_INSTALL = FMLCommonHandler.instance().getSide().isClient();
+
 	/*
 	 * random source, use it for item drop locations...
 	 */
@@ -402,6 +404,14 @@ public class Platform
 		return FMLCommonHandler.instance().getEffectiveSide().isClient();
 	}
 
+	/*
+	 * returns true if client classes are available.
+	 */
+	public static boolean isClientInstall()
+	{
+		return CLIENT_INSTALL;
+	}
+
 	public static boolean hasPermissions( final DimensionalCoord dc, final EntityPlayer player )
 	{
 		return dc.getWorld().canMineBlockBody( player, dc.getPos() );