When I press Brush Tool my game crash

[RobertDRN]

Hello everyone! When I press Brush Tool my game crash .. I need this tool to make edge of road.
I work with team to make Romania Map by Alexandru.
Thank you !

[Vøytek]

How are we supposed to guess?
As a modder, you should be able to investigate your game.log after a crash

[Minecart11]

My friend Sven had this issue when he was helping me with my Switzerland map. He ended up solving the problem by removing some def files.