Ah alright :)
I've tried this in several project where the clip lengths have been different.
In the project I'm working in at the moment I tried it on a vocal track that was about three minuets in total length.
I selected the silent parts between verses and pressed delete to get rid of the silence. After this I tried applying region FX on the still visible parts of the clip and got the crash.
After this I did the exact same procedure, except that I bounced the visible clip regions before applying the FX. No crash.
Thanks for the fast reply Seth! Hope you'll figure it out :)