This has been happening very frequently for me recently as well, although I am on v20.0.3.0 (so maybe v22 beta discussion is the wrong place to comment) and only have one instance running. In my case, vslick.sta gets deleted. I'm assuming SlickEdit deletes the old file and tries to write the new file and just fails somehow. I setup a scheduled job to make a backup copy of vslick.sta every minute, and put it back if it gets deleted, but unfortunately that doesn't help.
Also, once it gets into this state, I can't close SlickEdit normally. If I try, I get a dialog that says:
Spill file I/O error.
The spill file is currently set to .
To change the location of the spill file, go to Tools > Options > Application Options > Virtual Memory.
[Retry] [Cancel]
(Note that I haven't changed the spill file, the Spill file path entry in Tools > Options > Application Options > Virtual Memory is blank.)
The Retry button does nothing, by which I mean either nothing actually happens, or it just shows the same dialog again, I can't really tell. The Cancel button just results in another dialog that says:
Error reading file
[OK]
The OK button just shows the first dialog again, ad nauseam. Eventually I have to kill vs.exe via task manager.