Hello, @block_busterNL
Please reconfirm the installation location of Winter Mod: (You can find some information here.)
https://truckersmp.com/knowledge-base/article/84
And verify the integrity of the Winter Mod:
Currently, TruckersMP supports the following mods:
ETS2:
-frosty_8.scs
-frosty_heavy_winter_8.scs
ATS2:
-frosty_ats_v3.scs
-frosty_heavy_winter_3_0.scs
Hope I can help you and Merry Christmas!
Sincerely,
Tony