Factorio Forums

After i create multiplayer game, and my friends join, if someone gets hit by enemy - we get desync... after game finishes synchronizing and unpouses situation repeats emediatly... so we get stuck in sync loop, which can be solved only with alt+f4.
We are playing Windows x64 version via Hamachi network.

Can confirm that this also happens when a friend and I play. The moment we take damage from a biter/spitter/worm we have the same desync.

EDIT: The issue seems to be when once player is using the 32bit version of factorio on windows and another is using 64bit version of factorio on windows. Both OS's are Windows 8.1 64bit.

I can confirm this. It desyncs when we get hit and often when the walls are being attacked. We also play 32bit and 64bit version in a 2 player game. Both OS are Win7

Edit: I switched to 32bit so that both players had the 32bit version. This fixed the issue.

this makes me wonder what random function the devs are using for Factorio, because it seems like 64bit players are using a different function to the 32bit players, which in turn generates different random values, which in turn generates different events on either end, which in turn causes a desync.

if they're using the built in functions from the latest C++ Specification (assuming that's the language), then it is possible the compiled code uses a different random function.

However, that leaves me curious as to why only taking damage causes a desync, random is used extensively in the game, for example, when biters choose to attack, which biters spawn, generating new areas of map, etc.

yes.. installing same version for every player totaly fixes the problem

This is probably related to the pathfinding desync problem, so it should be fixed for 0.11.4.