[DanCooper]

I found the reason!

When I encoded the bluray, I made a small mistake in the file name:
My mistake was to have put a "." instead of a "E" between the season number and the episode number

This file name crashes EMM:
THE LAST KiNGDOM S01.01 MULTi 1080P BLU-RAY DTS x264

This file name is recognized by EMM:
THE LAST KiNGDOM S01E01 MULTi 1080P BLU-RAY DTS x264

hope this helps in the future

Thank you, I'll check this!