New on Unity - problem with rockVR

Hello,

I am new on Unity and I would like to record a 2 min video from a project in Unity.
I download VR capture and i followed all of the steps to make it work.

But, when I push the button "play" to make the record begin, the software tell me that the capture is probably not writing anything and when I push the button stop, Unity crash...

Have you got an solution ?

Thanks (Sorry for my english)