i can't save my work. I lost all Save, Save As, Undo functionality (everything is grayed out).

[Noah Eo]

suddenly  

1. Can not Save / Save as

Important functions is deactivated.

Everytime i make new document and then after push comand+S

it doesn't at all !!!!!!!!!

2. Can not Undo

it's MASSIVE PROBLEM for me. i can't work anything......

Please HELP ME to fix BUG