have you checked the AVG history (menu History -> Resident Shield, Online Shield, etc.), which file was blocked? Have you checked the situation with disabled AVG Firewall?
Else as you are using paid AVG, please contact our AVG technical support, which have enough tools to help you with this situation, on address:
I am running AVG Internet Security 9. I logged into facebook and tried to watch one of the videos that I uploaded to my profile and I received an AVG alert. I clicked the OK button and now I am unable to watch any of my videos or any of my friends videos. I tried to disable LinkScanner and some other things then restart with no luck. I couldnt find anything in the vault or anywhere else. Any help would be greatly appreciated. Thank You