You could try following the advice the error message gave you and post the results of a backtrace here but I doubt there is much we can do about it.
I don't think I have the skill to do that. Sorry.
I tried reinstalling geany and I'm not having the issue anymore, I think. Anyway, maybe this is not a geany bug as mentioned since I'm using it on openbox before and it just works fine. I'll just close this issue then.