I`ve already found the solution, just set the privacy settings for the camera and the microphone to allow apps to use them.
Worked for me.
I know that it would´ve been better to start a new thread but i searched for a solution an found this one an i dont think that i am the last one.
Sorry for posting again.
hi, sorry for writing in such an old post, but i have the same problem. This post worked for me but just for a few seconds and then the capture card was gone... any idea what the cause or solution of this problem is?