I've never seen that happen. I've seen it take a long time to scan a zipped or encrypted file but it always resumes by itself.
Run the Virtual Technician to check that everything is OK. Also make sure your system is totally up to date.
PC is set to "never" sleep while monitor is set to sleep after 15 mins of inactivity. Problem is always after a screen sleep. McAfee Virtual Technician found & fixed 2 problems.
Could you kindly provide us a 'Screenshot' of the (Problems found) by MVT? I have to concur with Colleague 'Ex_Brit' that I have never experienced that. I might add that with the Latest Version/Build of 'Virus Scan', it started and completed without any incidence.
In addition, could you provide your most current Version/Build as it will help us to further assist you.
All the Best,