Anyone know what causes this?

Hello Terry. Please have a look at these articles. 1) http://avgclick.me/reportafalsedetection  2) http://avgclick.me/AddException

I have Microsoft flight simulator X installed on an SSD and the drive allocated the designation O:
Frequently when closing the program AVG antivirus pops up.
Threat: General behavioral detection
Object name: C:2\PROGRAM FILES (X86)\MICROSOFT GAMES\MICROSOFT FLIGHT SIMULATOR X\FSX.EXE
Selecting 'Protect me' causes something to happen after which I am asked to restart the machine.
FSX still starts and runs.
Anyone got any ideas?
TIA
Terry

Hello Terry. Please have a look at these articles. 1) http://avgclick.me/reportafalsedetection  2) http://avgclick.me/AddException