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Assassin's Creed Mirage crashing on launch - any help?
Jarmer Nov 8, 2023
Hi, I finally am ready to do a playthrough on this game, and was very excited to get back to the core of what AC games meant years ago! I had actually successfully launched it a while back when it came out just to test it, but then gotten busy. So today I went to launch it, and I get an error on launch and can't seem to do anything, here are the details:

- installed the ubi launcher through the steam method of "add non steam game"
- the ubisoft connect launcher launches successfully
- I then click on the Mirage game, and try to launch it
- I get an error that states "non-dx12 video card - Unable to initialize graphics system. GPU does not support DX12."
- I can only hit the "ok" button and it crashes, nothing else.

I have a radeon 6800 xt so it definitely supports dx12. Anyone have any ideas on this? Is there some kind of command line launch stuff I could add it to force it to see my gpu?

I should mention I have tried with the most up to date Proton Experimental as well as the Glorious Eggroll - neither works.
This topic has an answer marked - jump to answer.
Grogan Nov 8, 2023
Only you will know what's changed on your system since it last worked. Do you have any other DirectX 12 games to test with Proton?

It's possible the game has changed, maybe it's asking for a different feature level than you are advertising or something.

You could try testing some variables in launch options of the "game" that is your Ubisoft client

This is an undocumented variable. I can see the supported levels in the source code for vkd3d-proton. Current Proton-GE would have a pretty recent vkd3d-proton checkout, so...

VKD3D_FEATURE_LEVEL=

feature_levels[] =
    {
        { "11_0", D3D_FEATURE_LEVEL_11_0 },
        { "11_1", D3D_FEATURE_LEVEL_11_1 },
        { "12_0", D3D_FEATURE_LEVEL_12_0 },
        { "12_1", D3D_FEATURE_LEVEL_12_1 },
        { "12_2", D3D_FEATURE_LEVEL_12_2 },
    };


Try advertising different feature levels in your Launch Options. Try a higher one first. Start with:

VKD3D_FEATURE_LEVEL=12_2 %command%

Be prepared for disappointment, this is just a shot in the dark.
Jarmer Nov 8, 2023
@Grogan, thank you for the suggestion! Unfortunately it did not work. Still same error. I did find a reddit thread from the steamdeck sub that is just a bunch of people with the same issue.

So I'd imagine we'll need to wait on a proton hotfix or GE hotfix. There was a large 4.5 gb update to the game itself that I had to download before it would launch, so I imagine something in there broke the wine layer?

Here's the thread I mentioned:
https://www.reddit.com/r/SteamDeck/comments/17qd62h/assassins_creed_mirage_error/
Grogan Nov 8, 2023
Ahh shit, and I'm seeing new threads in there since that one (e.g. 30 min. ago)

Sorry it's broken. I'm not getting it because it's Ubisoft and Epic stores exclusively, but I otherwise would have been interested.

It's a popular enough game that I'll bet people are on this already and there should be workarounds soon.
Jarmer Nov 9, 2023
got it working! In case anyone else is having this, you can either:

1- wait for proton experimental to be updated with the fix
2- switch to use proton experimental bleeding edge within steam
3- or, using regular proton experimental, add the following launch options to the ubisoft connect "non-steam game" launcher:

WINEDLLOVERRIDES=amd_ags_x64=b %command%
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