(https://i.imgur.com/0cuw31L.mp4) Here is a video of me reproducing the problem. I don't believe the bit depth was important. In the video, I first exported a smaller image. Afterwards, I exported a very very big image and it crashed. So, it seems the problem may have been the the size of the large pretty image.
(https://i.imgur.com/0O1xZij.mp4) Here is another video where I save as a `.ourpaint` file. It crashes just as well, however the file it wrote (`i_am_testing.ourpaint`) had 178 bytes of data in it after the crash.
When I recorded the first clip, I had about 50 gigabytes of RAM available out of 64 gigabytes. Upon export, Task Manager showed OurPaint using 15 gigabytes of RAM before the crash (do note that Task Manager may lag behind).
There were 90 gigabytes of space in the drive I attempted to export to.
Perhaps automatic backups would help ease users in situations such as this? (And if the backup itself causes the program to crash, at least it crashes early in a user's session)
:)