This may or may not be related to my other thread?: https://forum.adguard.com/index.php?threads/win-7-x64-adguard-6-3-974-and-ie11.28622/ That said, what i have found out after much head banging off desk is that AdGuard is causing YouTube videos on Win7 (64bit) to crash. I know this because with AdGuard enabled any and all videos i try to run on YouTube when i use IE11 will crash at some point, they start to play and the length they play varies but it doen't matter if it's a 40 sec video or a 30+ minute video, the end result is the same... AdGuard WILL crash the videos at some point. If i exit Adguard and disable filters (unknown at this point if the filters are relevent) then ALL YouTube videos play in their entireity without issue. Also notable is that the buffering YouTube requires to enable seemless playback is also much improved. It's as if AdGuard is throttling YouTube to the point where Youtube gives up and bails out. Whatever the cause, here's a couple of example videos that have issues with AdGuard running (truth be told you could pick any video!) that no longer have issues without AdGuard, and their corresponding YouTube error screenshots: AC/DC - Thunderstruck (Official Video) HMS Vanguard run aground on way to breakers 1960 I hope that makes sense, and helps.