Subnautica 2 early access crashes

Issues & Assistance
1

Subnautica 2 early access launches to a splash screen and audio, but gets no further, then I get a popup saying the program is frozen and will be shut down.

Kernel is Linux 7.0.9-1-cachyos.

Nvidia driver is 595.71.05.

Steam Compatibility - I’ve tried:

  • default
  • Proton 7
  • GE proton 10-34
  • Proton CachyOS 10.0
  • Proton Hotfix
  • Proton 11.0 beta

I also tried the command that worked for original Subnautica with default Steam compatibility:

WINEDLLOVERRIDES=“winhttp=n,b” %command%

Have any of you gotten Subnautica 2 to run under Cachy? If yes, what is the magic spell?

2

I’ve got a similar setup to yours, for the game to work for me I had to use Proton 7.0-6 exactly.
I did not use any launch options.

3

This command I found on the Steam website enables the game to work. I made it through the intro and into the main game. The command:

VKD3D_DISABLE_EXTENSIONS=VK_EXT_mesh_shader,VK_NV_raw_access_chains %command%

This is with Steam compatibility GE-Proton10-34.

I tried Proton 7.0-6, but got a Direct-X error.

Update: proton-cachyos-10.0 also works with the above command.

4

I can play it with Proton CachyOs 11. (20260506) however I get a crash after 30min to 1 hour.

I have not yet tried the extra commands. The funny thing is I could play it for ~16h before I got the first crash but then I lost my savegame after the crash and the hotfix update. Either might be responsible.

It’s a bit of a question of what I really need to wait for, game update or Cachy updates, or Nvidia driver updates…

EDIT: Seem to have luck with the command mentioned by @Cachied

FYI:

Operating System: CachyOS Linux
KDE Plasma Version: 6.6.5
KDE Frameworks Version: 6.26.0
Qt Version: 6.11.1
Kernel Version: 7.0.9-1-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 9 5900HX with Radeon Graphics
Memory: 32 GiB of RAM (31,2 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 3080 Laptop GPU
Manufacturer: SchenkerTechnologiesGmbH
Product Name: XMG NEO (CZN/E21)

5

Something that has worked for me in a lot of games that freeze-crash on launch is a frame cap in mangohud. Usually something like 60fps and then remove it after boot. That did happen the second time I played and. If that doesn’t work, make shore that foreground-booster(dmemcg-booster) is activated.

6

I also cap FPS to 60 (because who wants to burn out and buy hardware in this economy, and even electricity is going up) but I’ve otherwise had few issues with Subnautica 2. Different hardware though: AMD GPU, AMD CPU, using the default proton that Cachy likes to start with.

Running all settings Epic in 5120x1440