You may succeed with giving the kmsgrab system admin capabilities, it does no longer require explicit sudo then.

sudo setcap cap_sys_admin+ep /path/to/kmsgrab

https://linux.die.net/man/8/setcap
https://linux.die.net/man/3/cap_from_text
https://man7.org/linux/man-pages/man7/capabilities.7.html

I did not debug to the end, but I strongly assume at some point DRM hits this method, which bails out with -EACCES ("Operation not permitted") when privileges are not met.

@muldjord thank you, yes the gamelist was generated and the links were ok. The videos were downloaded in the wrong format, so i converted them on the laptop and replace them in the /images folder. Now they work.
Thanks for the help

There is a thread about this.

for the future i now know the es_log.txt file could be interesting to have a look at first. Thanks