I found something strange. While typing in Scrivener in fullscreen mode, I eventually decided that I didn’t like the main charater’s name and did a Find and Replace, using Replace All to change all occurrences of the name.
After I did that, I found that for some reason the last two paragraphs I had written had been deleted. I hit command-Z to undo, but while it DID undo the name changes, it did NOT restore the deleted paragraphs. So I hit Undo again, but nothing happened, and when I went to the Edit menu Undo was grayed out. So those paragraphs were forever lost…until I retyped them.
So a couple of paragraphs were lost. Big deal. But then, a while later, I decided I still didn’t like the name, so I did Replace All once again. And again, the last couple of paragraphs I had writted were deleted. I tried Undo, but it did not restore them no matter how many times I tried to Undo.
And then the REALLY weird thing happened. I hit Escape to exit fullscreen mode, and lo and behold, the ENTIRE section I had been working on was gone!
I tried switching to other sections and switching back, no luck. I couldn’t Undo. Finally I closed the entire document, and when I reopened it the lost section was back! All but the last couple of paragraphs, that is…
I tried to reproduce it by typing a short story featuring a fellow named Bubba. After a few paragraphs, I did Replace All to change the name to Cletus. It seemed to work okay.
Then I wrote a few more and changed the name to Harry. This time, it only changed the last couple of instances of Cletus to Harry, and when I exited fullscreen the whole story was gone. After closing and reopening the project, however, it was back. I couldn’t make it delete the last couple of paragraphs again, though, but it may have had something to do with the length of the story.
P.S. This also happened when not in Fullscreen mode.
EDIT: One more thing. When I tried to reopen the Bubba project after closing it, Scrivener crashed. When I reopened Scrivener and then the Bubba project, the section was still intact. This only happened once out of several attempts, however.