I am the only one who has this problem in my friends group,
it occurs on both my laptop and my desktop as well as different internet sources.
When ever I try to join my friends with the RSO mod enabled, it gives me a mod settings mismatch screen that crashes my game when I press yes. I isolated it to RSO after 5 hours of uninstalling, reinstalling and testing mods on my friends server. So I have a pretty good feeling about this. is there any setting that i can change to help with this? Thanks for your time.

+1 have the same problem. Seems that most RSO configs are not picked up when starting it on server headless mode.

I'm pretty sure you need to post a bug report about this on forums. Mod only defines settings - it has nothing to do with sharing or synchronizing them.

There is a bug fix for 0.15.7 that should fix this issue.