Saturday when I tried to start up Microsoft Flight Simulator 2004 (FS 2004), the dynamic File Shield scan in my Avast Virus Software determined the bus.mdl files for the 5 different elevation levels of my Mobile Control Tower addon (unchanged since 2004) to be suspicious for what it calls the Win32:Evo-gen [Susp] virus and placed them in its Virus Chest. However, when I scanned them with Avast in either the Virus Chest or in my Mobile Control Tower backup folder, all five files are found to be virus free. I have also scanned my Mobile Control Tower backup folders with Microsoft's Security Essentials and that also found no virus infections. I have informed Avast of what appears to be a False Positive by their File Shield scan and await their response.
Meanwhile I made the mistake of taking the lazy man's option of using the Avast 24/7 Technical Support line to quickly get help in working around this problem in order to get my FS 2004 setup back running. Unfortunately whatever offshore group that Avast has contracted out their Technical Support to was only interested in pressuring me to pay for an unnecessary and quite expensive PC cleanup service instead of helping me either exclude these bus.mdl files from the Avast File Shield scans or as a last resort turn the Avast File Shield scan off all together.
Needless to say, the discussion got heated as I pushed for a workaround to these false positives and the so called technical support person tried to convince me that a bunch of harmless files such as temp files were the cause of my problem and that I should pay them for their PC cleanup service. She finally gave up and hung up on me after telling me that there was no way to exclude these bus.mdl files from the File Shield scans or to turn the File Shield scans off. The moral to this story is to not be lazy like I was and bother to use the free Avast Technical Support line because it appears to connect to a scam for an essentially useless PC Cleanup service.
The good news is that subsequently I hunted around in my Avast Virus Software on my own and first found how to turn the Avast File Shield scans off so I could get the 5 Mobile Control Tower bus.mdl files re-installed and get my FS 2004 setup back running. Later I found how to exclude the 5 Mobile Control Tower model folders from the File Shield scans so I could have it back on when running FS 2004.
I'd like to notify Avast of my bad experience using their 24/7 technical support line, but I can't find a telephone number to use to talk to an actual Avast representative.