I've had a few times where Ctrl-F doesn't work anymore, and now it happened again. Ctrl-F does nothing, and if I go to the Text->Find menu, I can only select Find in Files and Replace in Files, all the rest are greyed out.

I also get a "The Filelist for this Workspace has been changed by another application." on every Alt-Tab, and I have nothing else opened that touch the filelist so this is false.