So a few weeks ago I was drawing some sketches and doing some short animations in Flash. Everything was going fine until I got a message from my antivirus software that it had detected some virus or corrupted files, instinctively I chose to quarantine and delete it. The threat having been removed, I got back to flash and try to save my work... it crashed. I though "No big deal I saved a few minutes ago". So I wait for it to close itself down and attempt to relaunch Flash, an error message pops up: "Application failed to start, reason: (randomnumbers)". Despite the message I persevere to try and open it up, I get the message again and again. By this point I'm quite annoyed, and decide to uninstall it and go to Adobes website to re downloaded the 2-3 GB application. After having suffered through an eternity of slow internet connection, I finally get in installed again. I open it up, the same error message... It was about that time that it dawned on me, the antivirus blocked Flash. I go through the antivirus settings to try and retrieve the files. I find them, restore them, and launch the application... the same message again. On top of that the antivirus now wants to block the same files again. After having spent the entire afternoon trying to sort out the issue, I gave up. I uninstalled Flash (again) and started dwelling on the 2 to 3 hours of work I had done over the weekend resulting in nothing (not to mention the other 5 animation projects I had started/almost finished).
Morale of the story: Screw AVG.
TL;DR: Antivirus blocked flash, lost hours of work.