@KevinH: I was able to crash Sigil by deleting images with the 64bit 0.8.2 Linux and Windows versions.
Here are the steps to reproduce the crash with the Linux version:
1. Start Sigil by double-clicking
this epub that crutledge posted today.
2. Enable Preview by pressing F10. (Activate Book View mode, if you haven't already done so.)
3. Select all images and delete them.
4. Open the same file via the File menu (click Discard).
Sigil will crash while re-opening the eub. (Sigil won't crash if Code View mode is activated.)
The official 64bit Windows version crashes in the same way, but I had to repeat the procedure. I.e. I loaded crutledge's epub, activated Book View and the Preview window, deleted all images (without a crash), re-opened the same file and deleted again all images. When I tried to re-open the same file one more time Sigil crashed.
(The Windows version won't crash either, if Code View mode is enabled.)