After I am editing a Document, usually after a few hour of it being open, when I hit save, It takes me to the save as pop up and states "We cant't save this file because its's read-only. To keep changes you need to save the Doc with a different name."

This is erratic and only happens when I try to save after being in the file editing for a while. It does not happen every time either.

Let me know if you know of a fix.