I am having issues saving files. I'm running InDesign CC vs.10 on a 2012 Mac 2.9 GHz Intel i7 with the latest OS. When I first open a doc, everything seems fine. But i I do the smallest amount of work to it, the menu options for save, save as, check in, save a copy, revert, undo and redo are all grayed out. I tried resetting the preferences, and it worked for a moment, but now I am back to the same problem; no undo, no saving. The only thing I can do to save my work is to leave it in a "twilight zone" mode of auto-recovery or export to .idml, both of which are not preferred. I am a design student with many due dates, and it is becoming a huge time sink to try to fix this. Help is much appreciated!!!