An operation was attempted on a pin that doesn't exist in the DirectShow filter graph

Originally Posted by liltechdude

when i go back into WMP and try to play the file that originally had DRM on it, it would not play. I tried getting a license for another file that i have, and it would not play that one. The error i get is this: "An operation was attempted on a pin that doesn't exist in the DirectShow filter graph."

Have you installed any codec packs?

Do you run Windows XP Media Center edition?
If yes, try to download KB910393 Update for Windows XP Media Center Edition 2005. This patch will hopefully fix your problem.