An example of the problem
- Check your .sii file ( chassis / cabin / accessory / etc )
- check if there is a line “hide_in xxx”
- remove them
- done
Reference :
https://modding.scssoft.com/wiki/Documentation/Engine/Units/accessory_addon_data
https://eurotrucksimulator2.com/modding_changes_114.php#Hide%20following%20views
Source :
https://forum.scssoft.com/viewtopic.php?f=160&t=176424&start=2650