- Log into a private wiki
- Open VE
- Make some changes
- In another tab, log out (or get logged out accidentally because of session management bugs)
- Try to save
- Save dialog gets stuck. "Resume editing" doesn't close it, only escape does
- Log back in in another tab
- Save dialog is still stuck and you can't get it unstuck
- Switching to source mode is the only way to rescue your edit
On the network level, the serializeforcachekey request gets back a readapidenied error, and that seems to be what causes things to get stuck.