I'm coming with an update, and I found the issue.
First of all I'm using an ASUS TUF Gaming FX505DT with AMDGPU as integrated driver and NVIDIA as dedicated.
I'm also using https://github.com/Hyper-KVM/optimus-manager, this is a fork from Optimus-Manager which is actually made for Intel GPU/Nvidia, but this one works for my AMDGPU/Nvidia system.
Now i'm on hybrid, hence I'm using the prime-run configuration, before launching any game to use dedicated gpu. But if I change from hybrid to nvidia (using optimus manager) the game works just fine.
What I observed is that the game, ignores prime-run, and it really wants to launch using the iGPU (AMD).
Hearts of Iron IV - 394360
Issue transferred from https://github.com/ValveSoftware/Proton/issues/5110.
@Alphvino posted on 2021-08-23T18:27:53:
When i run hearts of iron4 from the paradox launcher(i start it from steam then it loads the paradox launcher) it crashes while using the dedicated gpu. I use optimus-manager in hybrid mode and the only game that gives problems is hearts of iron 4. Every game i launch has these launch options:
prime-run %command%
Every game works fine, only hearts of iron 4 seems to have problems.
(I have my laptop(ideapadgaming 3 15arh05) connected to a hdmi screen)
I open steam and then i start hearts of iron 4. At first it loads the paradox launcher and when i click start, the launcher disappears and then the paradox crash report shows.
PS: I can't get the proton log file, it doesnt even generate it
Problems launching the Crusader Kings III and Hearts of Iron IV launcher
Issue transferred from https://github.com/ValveSoftware/Proton/issues/9461.
@salitv1999 posted on 2026-02-03T10:00:07:
Name of the game with compatibility issues:
Hearts of Iron IV
Crusader Kings III
Steam AppID of the game:
Hearts of Iron IV: 394360
Crusader Kings III: 1158310
The game launcher does not start.
Steam shows the game as running, but the launcher window does not appear.
Hearts of Iron IV starts only when bypassing the launcher.
Mods (e.g. Millennium Dawn) cause the launcher to freeze or not appear at all.
Crusader Kings III also has launcher issues:
The game does not crash, but the launcher window never appears.
Steam shows the game as running indefinitely.
(If anything else is needed, please let me know and I will try to provide the required files, logs, videos, or screenshots.)
Hello @salitv1999, please add PROTON_LOG=1 %command% to Heart's of Iron IV's launch options and attach the generated $HOME/steam-$APPID.log to this issue report as a file. (Proton logs compress well if needed.) Also, please copy the contents of Steam Runtime Diagnostics from Steam (Steam -> Help -> Steam Runtime Diagnostics) and put it in a gist, then include a link to the gist in this issue report.
https://gist.github.com/salitv1999/c8caef1248a29f3273c99ff9c0c4a225 HOI4
https://gist.github.com/salitv1999/24bd9b86ab6cea31170de63de63d9a85 Crusader king 3
The problem is the same even with the "PROTON_LOG=1 %command%" command. I entered it in "Launch Performances."
(I launched Hoi4 with the command, but Crusader Kings 3 doesn't launch without it either, even with the command.)
proton 10.0-10x1 2026-02proton hotfixx1 2026-02PROTON_LOG=1x2 2026-02prime-run %command%x1 2021-08
Compatibility Report
System Information
I confirm:
Symptoms
Everytime when I need to run a game i have to run it with
prime-runto use dGPU, and the game crashes this way, I also have tried launching the game through terminal and I get the same crash.But when I launch the game with iGPU the game works.