In my case, I can randomly reproduce it by making (or loading) a project with a bunch of clips on the timeline, hitting the spacebar to play/pause clips, and then sometimes pitivi doesn't react and apport pops up.
In my case, I can randomly reproduce it by making (or loading) a project with a bunch of clips on the timeline, hitting the spacebar to play/pause clips, and then sometimes pitivi doesn't react and apport pops up.