Can't Save SL3 file, another process...

When I save ANY Storyline file I get an error that says "The process cannot access the file ... because it is being used by another process." or a similar error saying another person changed the file, etc.

Earlier posts pointed to security software interfering.

Thanks-Alex

UPDATE: Apparently Dropbox counts as a network drive. It is well known that you can't work from a network drive with Storyline. I didn't think Dropbox counted, as the files are stored locally, then synced with the cloud periodically.

Well, working from the hard drive instead of the Dropbox folder has seemingly stopped this issue. Dropbox must have changed their sync procedure or something, as I never had this happen before, but removing the file from Dropbox worked.