Hi, I have been having the same issue for the last few months. It doesn't happen all the time and doesn't seem to matter if I work off of our server or from my desktop. I can be working on a file (sometimes I have already managed to save it a couple of times) and I'll randomly get the message:
"Cannot save the document. It may be opened by other applications. Close applications and try again. You may also use saveas to save it into a new document."
I am the only person working on these files within InDesign. I can 'saveas' a new file but generally it's followed by InDesign crashing. If I try to restart InDesign I get the the message:
"Error: Your previous Adobe InDesign session has not yet terminated. Please try to launch the application later"
The only solution is to then restart my mac.
If I choose not to 'save' or 'saveas' then the file closes and I can generally open other InDesign documents and work on them but cannot open the file I had the issue with until I restart (or copy to desktop).
I am working with InDesign CC2014, but I was having the same issues with CC. I have also updated my mac to Mavericks but that hasn't solved it.
I have tried re-creating/resetting the InDesign preference files but that hasn't solved the issue.
It isn't just one InDesign file I'm having issues with, its lots of different ones, and sometimes everything is fine. The error messages sometimes pop up every few days, or like yesterday, I had to restart my Mac six times!
Have you had any luck with this issue, we are seeing it in our environment as well and it's quite frustrating.