I'm getting an inaccurate 'Cannot open database' error. The automated backup saved my butt without any work being lost. A big 'thank you!' to the developers!
However, my question is about the suggested cause. It doesn't seem accurate. Do you think the recent addition of for multiple database engines means the spectrum of potential errors changed?
Here's how I got to my failure. I understand a new release candidate is being considered... so it seemed a good time to do maintenance on the tree. After doing a RestorePoint backup, I ran each tool in the Tools->Family Tree repair submenu. Then started work again after Reopening the Tree. The next day, I had a lockup while pasting an 88kb text message copied from Thunderbird.
After about an hour of being busy, I had to use Task Manager to end the Gramps process.
After breaking the lock, the following message pops when trying to open the 8mb tree: