I get this error in Streamlabs OBS and OBS. This error can be caused by having all available encoder sessions in use (NVENC can only have 2 sessions open at a time on most GPUs). It would be really helpful to people that don't already know this to put something about it in this error message. Right now it looks like a graphics driver reinstall is necessary, but that might not solve the problem. This error is easily reproduced by purposely opening 2 NVENC sessions and then attempting to record or go live in Streamlabs OBS or OBS. Closing one of the sessions fixes the error.