One time I had a bug with filter mask layer - blur effect has been cropped. I almost published my drawing, but at last moment I had noticed this cropped blur.

Changing layers visibility back and forth reset the filter, and helped. But this bug it is dangerous - this bug can go to exported and published image (I use Ctrl+Shift+C for export) unnoticed, when filter mask bug it is no so evident.
I think, this requires to close Krita and reopen image before export, to reset filters rendering, to be sure that exported effects are reproducible. This is inconvenient.

Screenshot of copied (with Ctrl+Shift+C) image before and after changed effect layer visibility:
http://dobrokot.ru/pics/i2016-01-04__21-03-41_124kb.png