"Mod contents are different even though versions are the same" error caused when connecting in multiplayer with different settings. The game cannot resolve this error automatically, and mods must be coded to handle all settings with identical code rather than conditional imports. :|

To clarify: This was caused by enabling both startup settings checkboxes, for capsule and "safe" ammo, then someone trying to connect without those enabled.

sounds like a bug with the game..
i thought you gotta restart the game when joining a server with different startup settings

The game does automatically restart to apply settings, but it can only apply settings after it verifies that the mods are truly identical. If the mod generates different code (using conditional require() imports) with different settings, the game sees it as being a different mod despite having the same name, and will not automatically sync the settings or restart for you.

i see, thank you very much.
it should work now