Can't join multiplayer lobby with same checksum and version (2024)

Does anybody know why my friend can't join my multiplayer lobby with the same mods, the same load order, the same checksum and the same version? The game keeps saying the host has different mods.

We even reinstalled the game, got the mods unsubscribed and subscribed again. But still this game does not let us play together. It seems CK III had this same issue if u load more mods then 1... pathetic

same problem.

All mods in the same order, same checksum, verified game files, unsubscribed and resubscribed.

AtomicBlastPony said:

Good news guys, u/Takeida on Reddit found the issue!
Apparently modded multiplayer only works if you have Victoria 3 installed on the same drive. So all players must have it installed on C:, for example.
Some mods still don't work in multiplayer regardless, but others such as the AI mod and automation mod now work properly!

Click to expand...

... Nice job, Paradox.

AtomicBlastPony said:

Good news guys, u/Takeida on Reddit found the issue!
Apparently modded multiplayer only works if you have Victoria 3 installed on the same drive. So all players must have it installed on C:, for example.
Some mods still don't work in multiplayer regardless, but others such as the AI mod and automation mod now work properly!

Click to expand...

As Pony mentioned, you all need it on the same drive, yeah. I'd like to add a few bits for stability:

• Always start on Speed 1. Give it one or two full week ticks, then up to speed 2. Give it another week or two, then you can up to speed 3. This makes sure to avoid desynch issues early into the game start, especially for bigger lobbies. If you're playing vanilla and have only a few people, you can go to speed 4 as well. But if you start having more people (let's say more than 3) and/or are using mods, it's best to stick to speed 3.
• If someone gets hit by an OOS, have everybody restart their game and rehost it. When one OOS hits, you'll get hit by them constantly from that player until a rehost is made and the save is transferred. If someone crashes, you can still hot-join as normal. Just keep the game paused at all times until they are fully in. In case of a crash and hot-join rejoin, try not to touch anything until a week ticks over. Helps reduce the likelihood of OOS further for me, but that might as well be confirmation bias.
• Interact as little with the war systems during an active war as possible, be it PVP or PVE. War, at the moment, is the biggest creator of CTD in multiplayer, the battles and front specifically. If you need to interact with generals and the like, best to do it directly through the warfare menu in the left when possible. When you have to interact with battles or fronts during an active war, try and take it slow instead of blitzing through all the options at once, lest you end up hard crashing.
• Best way to forcefully update mods (in case one has it updated and the other doesn't), is to unsubscribe from the mod, resubscribe, and verify local files for the game.
• If you're getting hit by "Host is running different mods" even when you both have the same checksum, mods, and game installed on the same drive, the mod in question is most likely messed up for MP. Drop the problem mod in question and grab something else.

elektrizikekswerk said:

If not already done, please file a bug report.

Click to expand...

There's a similar bug report already.

FluffayOne said:

As Pony mentioned, you all need it on the same drive, yeah. I'd like to add a few bits for stability:

• Always start on Speed 1. Give it one or two full week ticks, then up to speed 2. Give it another week or two, then you can up to speed 3. This makes sure to avoid desynch issues early into the game start, especially for bigger lobbies. If you're playing vanilla and have only a few people, you can go to speed 4 as well. But if you start having more people (let's say more than 3) and/or are using mods, it's best to stick to speed 3.
• If someone gets hit by an OOS, have everybody restart their game and rehost it. When one OOS hits, you'll get hit by them constantly from that player until a rehost is made and the save is transferred. If someone crashes, you can still hot-join as normal. Just keep the game paused at all times until they are fully in. In case of a crash and hot-join rejoin, try not to touch anything until a week ticks over. Helps reduce the likelihood of OOS further for me, but that might as well be confirmation bias.
• Interact as little with the war systems during an active war as possible, be it PVP or PVE. War, at the moment, is the biggest creator of CTD in multiplayer, the battles and front specifically. If you need to interact with generals and the like, best to do it directly through the warfare menu in the left when possible. When you have to interact with battles or fronts during an active war, try and take it slow instead of blitzing through all the options at once, lest you end up hard crashing.
• Best way to forcefully update mods (in case one has it updated and the other doesn't), is to unsubscribe from the mod, resubscribe, and verify local files for the game.
• If you're getting hit by "Host is running different mods" even when you both have the same checksum, mods, and game installed on the same drive, the mod in question is most likely messed up for MP. Drop the problem mod in question and grab something else.

Click to expand...

None of this works. Me and my friend combined all of our mods into a single big local mod, and it worked fine... until we saved and went to bed. Next day, OOS a few ticks after loading the save. Nothing you mentioned helps fix it at all. The save is pretty much dead. Most of the time the issue is "ShippingLanes" but sometimes it's "RANDOM_COUNT".
If we host a new game, save it and try to load this save, everything works fine, so the issue was specific to that run. Loading earlier saves from the same run also causes OOS.
Playing the save in singleplayer for a few ticks, then hosting again still ends in OOS.

EDIT: Found a solution, OOS was caused by some wars waged by the AI. So I opened the save in singleplayer, tagged over to the AI nations and made them white peace. That worked!