Fatal error MCC

[kachapman]

A popup appears as I attempt to launch the game, with fatal error. It happens on a clean install on my steam deck and my laptop running fedora. Both have the DLL copied and launch parameters set. Tried many different regular proton and GE versions. No change.
The game runs fine without the mod file. Has a new update killed the mod?

[Reonu]

Same issue here, did you figure it out?

[kachapman]

No, we've just lost the ability to play multiplayer altogether. There's too many desync issues when we try to play coop on our own copies, even if we're all on the same platform. It's really ridiculous that they intentionally disabled split screen and didn't even provide a stable online multiplayer alternative.

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On Sunday, 10/19/25 at 12:27 Reonu ***@***.***> wrote: Reonu left a comment [(WinterSquire/AlphaRing#124)](#124 (comment)) Same issue here, did you figure it out? — Reply to this email directly, [view it on GitHub](#124 (comment)), or [unsubscribe](https://github.com/notifications/unsubscribe-auth/APF2YD5KT6BJHUC3GQIF4TL3YO3VVAVCNFSM6AAAAACJS25TA2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTIMJZG44DINBVGY). You are receiving this because you authored the thread.Message ID: ***@***.***>

[SAND-MADNESS]

Having this issue on my steamdeck as well with the new DLL! Worked perfectly and now pops up that Fatal Error window each time on GE, 10, and others.

[Reonu]

@SAND-MADNESS I solved it like this:
Go to go to steamapps/compatdata/ and delete the folder 976730
Then launch it with protonGE 10-15 and it will work (you can install this proton version with ProtonUp-Qt)

[slackerjerry]

@SAND-MADNESS I solved it like this: Go to go to steamapps/compatdata/ and delete the folder 976730 Then launch it with protonGE 10-15 and it will work (you can install this proton version with ProtonUp-Qt)

@Reonu trying to play on steam desk with 2 xbox controllers. I tried this. alpha ring panel showed up. did the setting (set 2 players -> assign controllers -> enable -> F4 close alpha ring panel). Yet, still can't add player2 in mission lobby. any suggestions? many thanks!

[ArmitageShanks]

@SAND-MADNESS I solved it like this: Go to go to steamapps/compatdata/ and delete the folder 976730 Then launch it with protonGE 10-15 and it will work (you can install this proton version with ProtonUp-Qt)

What does deleting folder 976730 do?

I just installed and ran MCC with GEProton 10-15 on my SteamDeck and that solved the issue I had.

[ArmitageShanks]

@SAND-MADNESS I solved it like this: Go to go to steamapps/compatdata/ and delete the folder 976730 Then launch it with protonGE 10-15 and it will work (you can install this proton version with ProtonUp-Qt)

@Reonu trying to play on steam desk with 2 xbox controllers. I tried this. alpha ring panel showed up. did the setting (set 2 players -> assign controllers -> enable -> F4 close alpha ring panel). Yet, still can't add player2 in mission lobby. any suggestions? many thanks!

Dumb question, but did you just try to start a mission? That's how it worked for me. Don't have to add any players in the lobby, just add two players with Alpha Ring, then close it, and then start the game you want. I only tried campaign mode though.

[slackerjerry]

@SAND-MADNESS I solved it like this: Go to go to steamapps/compatdata/ and delete the folder 976730 Then launch it with protonGE 10-15 and it will work (you can install this proton version with ProtonUp-Qt)

@Reonu trying to play on steam desk with 2 xbox controllers. I tried this. alpha ring panel showed up. did the setting (set 2 players -> assign controllers -> enable -> F4 close alpha ring panel). Yet, still can't add player2 in mission lobby. any suggestions? many thanks!

Dumb question, but did you just try to start a mission? That's how it worked for me. Don't have to add any players in the lobby, just add two players with Alpha Ring, then close it, and then start the game you want. I only tried campaign mode though.

OMG! You are absolutely correct! I was so dumb. I never really started the mission as I thought the lobby participants should show player2 lol lol lol It works perfectly now!

[SAND-MADNESS]

Wanted to reply and confirm that the above fixed it for me on my Deck! Thank you!!

[jggatter]

@SAND-MADNESS I solved it like this: Go to go to steamapps/compatdata/ and delete the folder 976730 Then launch it with protonGE 10-15 and it will work (you can install this proton version with ProtonUp-Qt)

What does deleting folder 976730 do?

I just installed and ran MCC with GEProton 10-15 on my SteamDeck and that solved the issue I had.

Can confirm that deleting the game's prefix dir, 976730, was the final thing I had to do to get it working!

After deleting 976730, Steam couldn't find it and was forced to rebuild the prefix. I don't know much, but this likely got rid of configurations that had been made for other Proton versions I tried + properly configured it for GE 10-15.

[kachapman]

Same here. Played through ODST last night with my son. We encountered a weird glitch at the beginning where there we needed to login to xbox live, but it wouldnt accept input at the sign-in screen. We fixed it by disconnecting all the controllers except 1 and then input worked. You could also just sign in before enabling the mod as well (I think).

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On Sunday, December 21st, 2025 at 9:29 AM, James Gatter ***@***.***> wrote: jggatter left a comment [(WinterSquire/AlphaRing#124)](#124 (comment)) >> ***@***.***(https://github.com/SAND-MADNESS) I solved it like this: Go to go to steamapps/compatdata/ and delete the folder 976730 Then launch it with protonGE 10-15 and it will work (you can install this proton version with ProtonUp-Qt) > > What does deleting folder 976730 do? > > I just installed and ran MCC with GEProton 10-15 on my SteamDeck and that solved the issue I had. Can confirm that deleting the game's prefix dir, 976730, was the final thing I had to do to get it working! After deleting 976730, Steam couldn't find it and was forced to rebuild the prefix. I don't know much, but this likely got rid of configurations that had been made for other Proton versions I tried + properly configured it for GE 10-15. — Reply to this email directly, [view it on GitHub](#124 (comment)), or [unsubscribe](https://github.com/notifications/unsubscribe-auth/APF2YD3QAK6OOAWL4D6K2FL4C2VERAVCNFSM6AAAAACJS25TA2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMNZYHA2DCNZZHA). You are receiving this because you authored the thread.Message ID: ***@***.***>