The encoding fails when using NVidia NVENC as hardware acceleration for recording
The latest build of FFmpeg included in the Multipurpose encoder requires the NVidia NVENC API version 9.
Updating the NVidia driver to the latest version should fix the problem.
Example of NVENC setting for the Multipurpose Encoder:
ffmpegLGPL.exe -i %PIPE% -c:v h264_nvenc -pix_fmt yuv420p -profile:v high -level 5 -preset hq -rc cbr_hq -b:v 16000k -maxrate:v 16M -threads 6 -c:a aac -b:a 224k -s 1280×720 -r 25 -f mp4 %FILENAME%