What is a locked profile?? Mozilla Firefox wants me to upgrade against locked profiles. Why?? I don't know what they are talking about. I either read items of interest from around the world, talk to family as I would on that old fashioned telephone and tell McAfee security how to do their business since I have been stolen and returned through Mozilla 2x's in 10-15 days but they can't catch them.
I would delete the current version of mozilla, and install the new version. Don't save the data, start over.
I would not use McAfee, and change to a better antivirus.
I would not use a free antivirus either.
Just saying, you may have some malware circulating in mozilla.