Another similar error message: show ArgumentError: Error #2015: Invalid BitmapData.
at flash.display::BitmapData/ctor()
at flash.display::BitmapData()
at com.runouw.ll.engine.levelData.items.data.platforms::Item_Planet/attach()
at com.runouw.ll.engine.core::Course/attachingItemsFrame()
I just got a similar error message as I was going through an Up-Down Level Splitter (it only loaded halfway past the loading bar, before stalling). I can't really elaborate, but this indeed happened in the same [left-right] transition as before.
I'm afraid this may actually be a level-specific issue, though, but the level I've experienced these errors with is still a WIP. However, I am actually pretty close to finishing it; I'm pretty much done with the final section, therefore - after that - I just need to design the big boss battle (and maybe an ending sequence), so hopefully my level will be finished before it is too late to look into these two errors messages. ...Unless it happens to be a general issue that can occur in any level, or if it could be solved technically without me having to provide the level code.