Same problem here. Have Ubisoft+, neither Watch Dogs Legion nor AC Valhalla launches, while AC Odyssey works flawlessly.

Same here :( , Origins and Odyssey works but not Valhalla. Block on Splash screen.

Same here. Still investigating the issue. AC:V is DXD12 (Feature List 12_0) only. Odyssey instead can run DXD11 as well. So I set the wine bottle to use DXD12 ( example ) but I'm facing another problem here with exceeded activations.
[  192]  2020-11-12 08:34:45 [  280] ERROR DenuvoGetGameToken.cpp (227) Get activation token server error: ExceededActivations.

This is what I tried to date:
- Installed a new instance of uPlay
- Configured it to use D3D12
-- added D3D12.dll (native, builtin) in winecfg
-- installed "vc_redist.x64.exe" in winecfg
-- set ENV variable: VKD3D_SHADER_DEBUG=none in lutris system options
-- set latest wine version "lutris-5.21-x86_64" with DXVK version "1.7.2L-5ca255d" (this adds D3D12 64bit and 32bit to wine)
- starting up uPlay
- verifying game files is successful now (ticket at ubisoft helped out)
- starting AC:V still gets stuck on splash screen with no activity (process shows up as defunct)

Last edited by bl-ckb-x on 12 November 2020 at 12:17 pm UTC

Guess we'll need to wait for Glorious Eggroll to pick things up, possibly with newest proton 5.13.

Also integrated Proton 5.13 as new runtime in lutris, even with forced use of D3D12 feature Level 12 (vkd3dfl12 parameter in user_settings.py). No change. It still gets stuck on splash screen. But there's still a high number of users in the ubisoft forums complaining the same effect on windows machines. Gives me hope it'll get fixed somehow.

Yes, Proton-5.13.2-RC3 doesn't fix things. Apparently VKD3D-2.0 is missing some calls, so does WINE (i.e. with regards to Speech API -- patches have been created, but not yet merged). Work needs to be done. There's currently no technology on the planet that will allow to run AC:V natively on Linux. Work is in progress.

do you think valve is helping with this, or do they dont care since ubisoft left steam

TL;DR: we just need to be patient and wait.

While this should be taken as an educated guess and nothing more, my take on this is as follows:
DX12 is inevitable. Support for it on Linux infrastructure is currently lacking, but improving each day. AC Valhalla will most probably come to Steam one day, because Steam is too big to ignore in the long run, and even if it won't, Valve is committed to Linux support and they'll want to use DX12 bells and whistles in their games under Windows sooner or later, while also keep them playable on Linux. We, the Linux users, are also no longer ignored in promotions like free games included with CPUs/GPUs, as there are promo-redeeming tools for Linux offered at least by AMD, and it's silly to give someone a gift that they can't use of. This is clearly the case with AC:V, that's offered by AMD to Linux users, yet they can't play it as of today: if you got AC:V from AMD, e-mail them and ask when will you be able to play it under your OS of choice. I think group of people that want to, yet can't/won't play new games on Windows is growing. There are also IOS users, which by themselves also put multi-platform support on the radar: if you have to support something else than Windows anyway, then why not also support Linux while at it? VKD3D-proton, while not targeted at AC:Valhalla, is under active development and it's primary goal is: "The project serves as the development effort for Direct3D 12 support in Proton." -- https://github.com/HansKristian-Work/vkd3d-proton

Oh, and there's also the fact, that apparently AC:V is not a crap game, and someone with knowledge and free time at their hands will set a goal of playing it under Linux, even if only because they can. :)

All that being said, I hope that AC:V and other new games support will come as an accidental result of ongoing work, as it should be. Holy grail-level state of things is Linux's compatibility with proprietary platforms that is reachable easily enough, so main game publishers will deem it as a worthwhile effort to just account Linux support during development instead of leaving things to community after release.

To do my part, I myself have a gaming-viable PC, yet I refuse to play games under Windows because someone has to. I could dual-boot, I could try to do some virtualization; I could go and buy a dedicated GPU only for PCI pass-through to Win10 VM, or I could buy a PS5, but I won't. Meanwhile I've cancelled my Ubisoft+ subscription and will resubscribe once there's a point to. I urge everyone to do the same: don't buy Ubisoft games on other platforms and wait until Linux support is announced either by Ubisoft or players reporting success. Unfortunately times are like they are; games are no longer developed out of clear passion; it's a business - and like with all business, you have to vote with money and patience in this case. Ask for Linux support on Ubi's support channels, so they know that it's no longer optional.

Thanks, Ofca! Totally agree here. I'll keep tinkering 'til this thing works. Last thing I tried out was copying the game into the wine bottle since comments came up saying it's problematic to separate the game installation folder to another drive. So this constellation pops up some crash dialogue on startup showing the same thing you already discovered: missing d3d calls, esp. d3dcompiler (I think).