not working nvenc ffmpeg

[vvulpes]

I solve my problem that was typed here before. I just delete Cover.jpg in attached in mkv.
For now, not working nvenc ffmpeg,


-> Creating jobs for source 1,...
-> Generating calls for: C:\work\test (1)-002_new_new.mkv
Current Output: C:\work\test (1)-002_new_new.mkv
 adding NVEnc (FFmpeg) calls for source: 1
 createJobs for C:\work\test (1)-002_new_new.mkv
  creating attachment extraction subjobs
  creating video subjobs
  creating muxing subjobs
  optimizing the subJobs
-> finished creating subjobs for current source
 added new job with id 18_19_16_7210
-> should be there after processing: C:\Users\vvulpes\AppData\Local\Temp\test (1)-002_new_new_18_19_16_7210_01.mkv
starting 18_19_16_7210_01_video@18:19:16.814 - C:\work\test (1)-002_new_new.mkv
finished after 00:00:01.330
-> 18_19_16_7210_01_video crashed: ERROR: C:\Users\vvulpes\AppData\Local\Temp\test (1)-002_new_new_18_19_16_7210_01.mkv is too small! (byteSize: 0byte)
Aborting '18_19_16_7210_01_video' due to: ERROR: C:\Users\vvulpes\AppData\Local\Temp\test (1)-002_new_new_18_19_16_7210_01.mkv is too small! (byteSize: 0byte)
Job 18_19_16_7210 finished!


And i have question, how to keep or improve grain on videos? What parametres i should take ?