Frazzeled,
Sorry to hear that...can you provide specific URLs/videos you are trying to play on both the web and mobile? The 3363 error only occurs on iOS.
If you are getting that for everything you try something else may be happening. If it's limited to specific channels on the app that will help us out. We've noticed higher errors on NBCSports (due to Tour de France) as well as MSNBC, Bravo, and E!.
For web, we are currently not seeing any issues. Can you provide the following when you get a moment?
1. Browser and OS used on Web
2. iOS version and app version used on mobile
3. Sample of 2-3 videos you've attempted to play on both web and mobile. A good example on iOS would be S7, E2 of True Blood or a full URL on the web such as: http://xfinitytv.comcast.net/watch/Modern-Family/6158438733133910112/124117059890/Three-Dinners/videos
Looking forward to getting you back up and running...
Thanks,
Matt