I just deleted a few buttons myself without any errors. The problem might be, that you've also deleted the graphics in the sprite folder.
To fix you problem, go to guiscript.asc and start at line 551. There you find lines like:
Comment out all those lines referring to the buttons you've already deleted - also for the other languages (in other words, do it 5 times)
This should do it
To fix you problem, go to guiscript.asc and start at line 551. There you find lines like:
Comment out all those lines referring to the buttons you've already deleted - also for the other languages (in other words, do it 5 times)
This should do it