Parsing Error message after exiting Elements

I am using Photoshop Elements 12 with Windows 10 and until a couple of days ago I was doing so without problems.  Over the last few days just after quitting the application I get a message "XML parsing error 'no element found at line 1'.  Although some advise I have seen online seems to indicate that this may have something to do with Nik plugins I could not understand or see a final answer over how to get rid of the message.  I have tried uninstalling and reinstalling Elements but the message has returned.  As yet I have not detected any other problems but am concerned that a warning message must have some point and therefore wonder if there is something going on that I should be trying to fix.  I should add that my Nik plugins were purchased some time ago before they were acquired by Google, so may not be able to rely on techinical help from that quarter. I am not a techy user so would welcome any straightforward help that anyone can give.  Thanks for any advice.