Does anyone know why this happens or how to resolve? Now I need to continue producing sheets and I am working with a file that will not save.
This is a little bit of a gamble but what I did was just close the file and it will ask you to save and it will work that way. No guarantees that it will work for you.
This happened to me several times. And it seemed to only happen when I tried to insert a block into my drawings in the Edition Layout tab. I can't confirm that this was the problem, though.
However, since I've updated to SP2 I haven't had this error pop up yet.
http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=21901541&linkID=12952913
Did you create link with Robot Structural Analyisis?
Sometimes I get that error after linking model to ARSA.