Factorio Forums

I don't really know what's going on here: the simulation works fine in single player, and all the vanilla simulations are working fine on this server. The migration file that it is complaining about looks fine to me (but why is it being applied to my simulation anyway?!).

To replicate, join the public Redmew K2SE server (should be up for at least a week or two).

The issue here is not within the migration, but that there is a migration at all. We don't allow migrations to happen in multiplayer, as those are a clear sign of a version mismatch. The bug I see here is that this logic is erroneously applied when loading saves for simulations as well.

The reason the migration is applied is simply that the savefile given as a base for the simulation was created without the mod named in the error message, so the loading process tries to apply all migrations that mod has, and the same for all other missing mods. Vanilla simulations are spared from this, because none of them use a savefile as a base, and rather set themselves up through Lua scripts and blueprints.

That being said, the issue has been addressed. Coming next release, these simulations will work in multiplayer as well.