You would be best to post on an independent forum for help with this. I think the Technical Support they refer to is Facebook's.
Download, install, update (important) and then run the free version of this application. Let it remove everything it finds and reboot when asked to.
Unfortunately, I have not been able to find a way to get any assistance from Facebook either. But, the good news is that for some reason, it finally worked. After getting the runtime error I let the page sit there and when I went back, it finally said no viruses were found so it must've run while I was away.
That's weird, maybe a server issue at McAfee's end. Glad it finally worked as I honestly wouldn't know who to contact on this.