Decided to go for a more "separated" TE registration.

This will still make it so addons still get to add custom blocks without having to change too much of the internals.

It still needs thorough testing though. I don't want to change this too much because it ruins older worlds.

src/main/java/appeng/block/networking/BlockCableBus.java

@@ -387,14 +387,12 @@ public class BlockCableBus extends AEBaseTileBlock
 		noTesrTile = Api.INSTANCE.partHelper().getCombinedInstance( TileCableBus.class );
 		this.setTileEntity( noTesrTile );
 
+		GameRegistry.registerTileEntity( noTesrTile, AppEng.MOD_ID.toLowerCase() + ":" + "BlockCableBus" );
+
 		if( Platform.isClient() )
 		{
 			setupTesr();
 		}
-		else
-		{
-			GameRegistry.registerTileEntity( noTesrTile, AppEng.MOD_ID.toLowerCase() + ":" + "BlockCableBus" );
-		}
 	}
 
 	@SideOnly( Side.CLIENT )