Whenever I try to save a file ChemDraw indicates that the file is already open and being modified by another program. Unchanged work is saved as a temporary file.

Whenever I try to save a file ChemDraw indicates that the file is already open and being modified by another program. Unchanged work is saved as a temporary file.

Typically this is caused by some antivirus software that is holding the file open. Restart your computer, disable your antivirus software, and retest the problem. If the problem goes away, make sure your antivirus software is up to date.