What happens when you try? What has changed on your system?
What version of ID, and what OS?
Its happening everyday x2 or 3. It used to happen a bit before on my old Mac ( was Indesign CS 5.5) but have just got a brand new Mac. Am running OSX 10.8.5. Indesign CC 9.2 - all new.
I'm thinking it could be my Wacom pen? (Intuosto 5)
When it happens - Command S doesn't work and even in the dropdown menu Save and Save As appear grey. I've been having to export to IDML and then close Indesign - then reopen.
There's nothing in particular different that I'm doing at the time. Just laying text and images into a book.
Am constantly doing saves then sometimes realising its not saving!
There are known isues with the Wacom Drivers and early versions of CC. Are both the drivers and ID at the newest patch levels?
I got new mac about a month ago then got what I think is the newest version of Indesign and downloaded the wacom driver suggested by wacom website.
Latest version of ID is 9.2.1. You'll have to check with Wacom on their drivers.