I believe you have to give the NAS drive the same network name as per the last post in this thread: https://community.mcafee.com/message/63068#63068
As I recalled this coming up repeatedly over the years, more often than not in the Business products section, I moved this to Data Backup in the hope that some of those experts might jump in but I see that they haven't thus far.
I trust that it is the home product you are using, if not I will move it again.
I'm afraid I don't use NAS but have my drives connected by eSATA so can't much help beyond that. However, if the above doesn't help I will flag it and hope someone does know what to say.
Meanwhile Technical Support Chat is always available via Useful Links above.
Many thanks for the reply. It is helpful to know that I am not the only one who has had this problem. I have just taken MacAfee off on of my PCs and installed Kaspersky. That has resolved all the networking problems on that particular machine!
That's a shame. Ah well, good luck!!