I am getting an Error Gen Failure 31 when turning on the stream for league of legends or payday 2. A little bit of research suggests that my card is compatible, but I could be wrong. Mini Ninjas streamed just fine, as well as sanctum 2 and borderlands 2. It looks great too. Solved all of my lag issues.
Solved: Games were not full screen. Can I run raptr without having the game full screen?
When I try to launch Magic the Gathering: Online from my library I get a connection error but can launch it from my desktop just fine. I get magic the gathering online connection error.
Potentially solved: The game is no longer supported by raptr.
AMD Radeon HD 7700 Series
To do my best to answer your questions:
Yes, you can run Raptr with a game running in windowed mode. However, you may run across issues with using GVR or overlay depending on the game.
For Magic the Gathering: Online do you mean you get a connection error from Raptr or the game? I'll need more detail before I can try to solve this one.