[2021] launching the wrong version

Please do a full **clean** re-install:

- move any valued save games elsewhere, and user_empire_designs.txt from /Documents/Paradox Interactive/Stellaris/ if you have made any custom empires or races.
- "uninstall" in Steam-Stellaris
- manually delete both the Steam/SteamApps/common/Stellaris AND Documents/Paradox/Stellaris folders
- re-install game in Steam, run a Steam Verify when done.
- add stellaris.exe to the exceptions list of your antivirus app; ESPECIALLY if you have Windows Defender, add it to the Ransomware "Apps Allowed Through" list.
- start the game with no mods active and test

In particular you need to make sure there are no files or folders left under either the Steam Stellaris or Documents Stellaris locations, before installing again.

That should do it for you!  

definenacl said: hello, I know this fix was created on may 7th 2020, but it sounded like a sort of universal fix for a checksum issue. I tried the above steps several times and I cant get the same checksum as my friend I am trying to play modded with. I got it to work once, but when I tried to continue our campaign the following day the issue came back. it is a list of 7 mods, I looked into the mods that we were using and it appears its not a known issue for any of them, we tried to get our checksums to match by removing 1 mod at a time to try and single out the issue, but that didn't work either. I tried uninstalling and reinstalling several times, and each time deleting the 2 stellaris file paths. I tried copying over the files in my friends stellaris folders, but that didn't fix it either. I used the irony mod manager, with the same mods, and we still ended up with different checksums even though they are the same set of mods in the same load order, I would greatly appreciate your help.

Can you two play MP with no mods at all enabled? This is to check if it is a mod issue or a game installation problem.

If you can then it is a mod issue of some sort. Both of you enable just one mod, see if you can play MP then. If so, then add one more, check again - this way you'll pin down which is the problem mod.