On occasion I’ve had issues with saving my Illustrator files. I create a new file or make changes to an existing one, but when I try to save I get an error message. This happened to me in Illustrator 11 and CS3. I tried saving the file in different formats to see if that would work… no go. The cause is that the Adobe Prefs file can become corrupted and then there are problems saving files.
The FIX: You need to delete the current Prefs file. Illustrator will create a new one when it runs again. To delete the file…
…hold down CTRL-ALT-SHIFT while starting Illustrator. Make sure that you hold it down until it is completely loaded. If prompted, select “Yes” to delete the current Prefs file.