[Modded] Desync and Disconnect on Steam Multiplayer when Host moves.

[Casper1123]

I will preface this by stating that I'm rather new to the forums and have not tested much with the individual mods to see if it's a modding issue and that I've been redirected here from https://www.reddit.com/r/factorio/comme ... are_button this reddit post comment (this is a post I made).

The issue:
When host uses a movement input, connected client(s) desync immediately and disconnect without recovery.
Connected clients are able to interact with the world without, moving without crashing anything. Host can (at the very least) open planetary maps and look around. Nothing else was tested so far (though we can always gather more data if needed).
This seems to be caused by a

Code: Select all

Multiplayer desynchronisation: crc test (heuristic) failed for crcTick(12052041) serverCRC(2709376315) localCRC(3331615774)

I am not technically skilled enough (yet) to be able to properly understand the desync reports generated by some of our tests.

I can confirm this issue is not present when disabling mods (tested in a freshly generated world with only base (2.0.72) enabled).
Additionally, I have not been able to detect any issues in pure solo play or while hosting the server alone as the host seems unaffected (because their movement kicks everyone out).

If need be I can supply more files. Thanks for your time regardless.

[Rseding91]

I'm able to reliably reproduce a desync with the zoom-based-exoskeleton-speed mod enabled and it seems to work with it disabled. In the linked reddit post you mention you tried disabling it - but both desync reports show it's enabled. Are you sure you actually disabled it?

Looking at the mod I can see why it would desync - it was never updated properly for the changes made in the 2.0 game release where the mod "global" table was renamed to "storage".

[Casper1123]

I explicitly remember disabling the mod when we started removing a couple mods that would have connection with movement and I restarted my game with this disabled first which had the issue persist; as such we concluded that it could not have been that mod but I will retest it later and contact the mod author if that's the issue. I guess I just didn't properly double-check?

[Rseding91]

It's possible more than 1 mod is causing the issue - I was simply unable to reproduce a desync without that specific mod. But if you still have issues with it removed please post the desync report.

[Casper1123]

It seems that it was indeed just this mod causing the desync. I thought I had disabled the mod, and I might not have (somehow), but deleting it works well now. Sorry for any potentially wasted time..