Zone Doctor+ problem

Ah, I see. TBH I did make some "creative" tiling in the last few changes. I'll experiment and see what it accepts to save, it's the only immediate solution. Thanks!

That message should not cause any problems except if you were to try to edit any tilesets after #74 which in that case I can only assume the edits will not save.

I would NOT recommend editing the tilesets though(overworld might be ok, i'll have to do some testing).  In my experience if you try to change one it tends to effect other tiles in the tileset you edit.  Normal map editing is fine but the actual tilesets have not been friendly to me.

I wouldn't recommend importing any maps either, everytime I have tried it has always caused ROM problems that make the editor unusable.  The only exception is when you import overworld maps, I have not had problems there.

I'm pretty familiar with the editor, let me know if you have any questions i'll do my best to help. You should definitely make a lot of backups until you get familiar with what stuff can cause errors.