I was working on matching a toptube curve to a background image I'd imported, and went to the File> menu (intending to >Save). The program hung here, without showing the full File menu dropdown, and without a normal border on said dropdown. All then appeared to be frozen, so I minimized the window, and brought it back, only to see black screen in the drawing field, with the standard menu bar, but still frozen.
I then shut down bcad, saved when prompted (hoping it would save the work I had done), restarted, opened ok with my default, and when I tried to open the [corrupted] file I had been working on, all I got was the default imported image dialog, with no change in the actual drawing field (eg. still showing default drawing template).
Restarted bcad again, no dice. Restarted computer, then opened bcad, still no change.
All other files appear to be working fine, it's just this one that does not open properly (i.e. imported image dialog shows up, but drawing field still shows default from program startup).