If a mod has non-Roman characters (specifically CHINESE) in it's name, then UNLESS you have CHINESE set as your default Windows language (having it as a secondary language option does not work) , then it will crash with this error message every time.
I installed Chinese as my default language, and it then works fine. I hope this is something Bohemia can work around ? I live in China, but am not Chinese, and do not wish to have Chinese as my Windows language just to be able to play specific modded servers. It also effectively allows Chinese servers to geographically isolate themselves from the community.
See screenshot for an example of a specific mod with a Chinese name. It does the same with other Chinese mods too.