Sometimes the undo buffer becomes completely unavailable. The only way to get the functionality back is to quit InDesign and relaunch it.
Also, in all the Adobe apps I often lose the option key or spacebar for shortcuts -- as if the keyboard shortcuts are inaccessible or mapped incorrectly. Switching keyboard shortcut sets to XPress shortcuts and back sometimes works, otherwise I have to restart InDesign.
Does anyone have any inside information about this or know if Adobe is aware of the issue? It is quite annoying and ruins my productivity.