I have the same issue.
A Windows message has popped up asking me to "Stop Running Script" - something about taking too long to respond.
But the McAfee 'busy icon just keeps on running !
I need to check just what is quarantined and trusted!!
Sounds like too many files there. A manual clean should fix this BUT if mcafee quarantined something you want you will lose it via this method.
Explains both posts above well.