Failed to open NVENC codec: Function not implemented

Under obs-studio suddenly cannot record or stream. Have installed latest drivers for GeForce GT 710 with:
nvidia driver 430.4 using from the official NVIDEA web site.

This is output from log file:

11:45:27 PM.029: [NVENC encoder: ‘simple_h264_stream’] settings:
11:45:27 PM.029: rate_control: CBR
11:45:27 PM.029: bitrate: 816
11:45:27 PM.029: cqp: 0
11:45:27 PM.029: keyint: 60
11:45:27 PM.029: preset: hq
11:45:27 PM.029: profile: high
11:45:27 PM.029: width: 708
11:45:27 PM.029: height: 400
11:45:27 PM.029: 2-pass: false
11:45:27 PM.029: b-frames: 2
11:45:27 PM.029: GPU: 0
11:45:27 PM.029:
11:45:27 PM.051: [NVENC encoder: ‘simple_h264_stream’] Failed to open NVENC codec: Function not implemented
11:45:27 PM.051: Stream output type ‘rtmp_output’ failed to start!

I then resorted to:
sudo ubuntu-drivers autoinstall

and eventually rolled back to nvidia-driver-390

This was all working a few days ago. I believe there was an upgrade or update and now I cannot stream or record on obs-studio.

Suggestions wouild be very much appreciated.

If you’re tracking the stable channel snap info obs-studio then it has bumped to ffmpeg 4.2. It’s possible this broke it. You may try snap revert obs-studio which should take you back to the previous release (based on the older version of ffmpeg and previous nvenc). Does that work?