I have a save I have been playing on with friends that I have just been hosting through the game UI every time we play. I'd like to run a headless server instead using our preexisting save. When I attempt to start the server with that save, I get a message saying

"Error while running event oarc-mod::on_init()
oarc-mod/control.lua:49: It appears as though this mod is trying to re-run on_init. If you removed the mod and re-added it again, this is NOT supported. You have to rollback to a previous save where the mod was enabled."

We started the save with OARC 2.1.0 and I was getting a similar message using that version. It would say something along the lines of "Error adding force. Force already exists". So I've updated the OARC version to 2.1.9 and I am now getting the message above. I have had OARC enabled on this save the entire time so I am confused by the message.

So the only time on_init is supposed to run is when the mod is new to the save. So if you're seeing that message, I don't know how else you could get that unless somehow a save was loaded with the mod, then without it, and then with it again...

The only solution is finding an older save without that problem or starting fresh I think. The only other person who saw this same issue accidentally loaded a save without the mod.

Not sure what was going on because I've always had OARC enabled for that save. I was trying to use an older version of my save so I just tried it with the latest version and it worked no problem. Thanks for the quick response, it seems to be working fine now :)

Glad it worked out! Let me know if you have any other issues. Thanks!