Fixing Windows Phone Error 3100 An error has occurred
No matter what I did, one Windows Phone 7 app always gave the following error when I tried to play some videos with it using the Microsoft Media Platform:
3100 An error has occurred.
What was worse, the same code and the same video worked in an another app.
Turns out, the reason was simple: Capabilities. In particular, the app was missing ID_CAP_MEDIALIBcapability.