I have the same problem as other are also facing.
My firewall will not stay on... the security center keeps popping up and when you turn the firewall on it clicks right back off.
Looks like this is a common problem with lots of threads, though I've searched through them and can't find a root cause for my problems. I don't appear to have the conserv.dll anywhere. I figured it was a rootkit, so I've run Malewarebytes, hitman pro, antizeroaccess, and Rkill and all of them have found nothing.
The only symptom I've found on my computer (other than that firewall won't stay on) is that my history on internet explorer is blank. Otherwise no indications anything is wrong.
Perform a manual update for your McAfee product & Run McAfee Virtual Technician (MVT) this is an automated self-healing tool that can diagnose and fix many problems related to your McAfee product.
You can download and run McAfee Virtual Technician (MVT) from http://mvt.mcafee.com/mvt
Kindly update me with the MVT Session ID