020052 likely means (20 seconds and 52 milliseconds) – but that’s oddly short. More plausibly:
For best quality conversion of nsfs324engsub (20m52s), use H.265 CRF 16, MKV container, copy subtitles. Provide exact source format and desired output device to fine-tune. nsfs324engsub convert020052 min best
Rename to remove strange characters ( nsfs324engsub.mkv ) and try again. 020052 likely means (20 seconds and 52 milliseconds)