Installation on Ubuntu 16.04 and Kubuntu 18.04, several recent versions of Bluefish including 2.2.10.
I do a Find and Replace operation, scope: Files on disk. While it is running, I hit the 'Close' button. Bluefish breaks down.
Reproducible: always.
Remedy: Best: Allow the user to hit this button (or a 'Stop' button) to stop a running operation. Second best: Deactivate the 'Close' button during search.
finally fixed in revision 8811 !