I just installed the game on my machine - running Debian 10. But whenever I try and launch it - it immediately closes (my screen gives a quick flash that looks like the application is starting in full screen - but I never actually see any graphics since it immediately closes).

Running it in the console, I see this:

```
Running Unbound: Worlds Apart
4.26.2-0+++UE4+Release-4.26 522 0
Disabling core dumps.
Xlib: extension "NV-GLX" missing on display ":0.0".
Xlib: extension "NV-GLX" missing on display ":0.0".
INTEL-MESA: warning: Haswell Vulkan support is incomplete
INTEL-MESA: warning: Haswell Vulkan support is incomplete
Signal 11 caught.
Malloc Size=65538 LargeMemoryPoolOffset=65554
CommonUnixCrashHandler: Signal=11
Malloc Size=131160 LargeMemoryPoolOffset=196744
Malloc Size=131160 LargeMemoryPoolOffset=327928
Engine crash handling finished; re-raising signal 11 for the default handler. Good bye.
Segmentation fault

```

Maybe there is an update that can be released to fix this? I saw on the Steam forums about a similar issue that it was suddenly fixed when a newer version was released (has that version been released here yet?).

---

For now, I am requesting a refund due to being unable to start the game. Maybe once more people have played it - newer versions released and others have figured out all the intricacies, I'll be able to repurchase.

---

I've returned to try and get this working once again. I've done a nice reinstall of a bunch of Nvidia drivers (to get some Vulkan support) and now I'm getting an error that "Cannot find a compatible Vulkan device that supports surface presentation." So I might just need better hardware.

For others having the initial issue, make sure your graphics card has Vulkan support.

Same here, but only that on console:

./Unbound.sh: line 5: 41063 Illegal instruction (core dumped) "$UE4_PROJECT_ROOT/Unbound/Binaries/Linux/Unbound-Linux-Shipping" Unbound "$@"

And this on system logs:

[32904.049173] traps: Unbound-Linux-S[40875] trap invalid opcode ip:2acd140 sp:7ffc650f6fd0 error:0 in Unbound-Linux-Shipping[202e000+3c47000]
[32981.320036] traps: Unbound-Linux-S[40949] trap invalid opcode ip:2acd140 sp:7ffd80ae00a0 error:0 in Unbound-Linux-Shipping[202e000+3c47000]

The Prologue demo is working very well.

What CPU has your PC got? "Illegal instruction" can mean the program's been compiled with optimisations that need a more recent one.

It's a Phenom X4. Certainly an SSE3 instruction or something like that that didn't make it into Prologue or Windows release (this one runs).

I haven't purchased yet, but I noticed, that the sales page says: "OpenGL not supported"; which is strange. It could mean that is is either unaccelerated or uses Vulkan. You need pretty modern harware (GPU at least) for Vulkan and a working driver implementations (AMD's RX and more modern should work, iirc. the free driver stack also supports slightly older models and several APUs, even down to Kabini).
The illegal instruction... could be a different wording for illegal opcode for the CPU, then the compiled version uses something that is not present on the Phenom. However this game shouldn't need that much CPU power and Phenom still is powerful. On the other hand, it could also be something else (not opcode related). The sales pages system requirements say just "multicore 1.8 GHz" which is very plain and could be nearly every x86/amd64-CPU made in the last 10 years, besides maybe some near-embedded x86 like Atom. Even some ThinClients have CPUs according to these specs.

Interesting hint: People on protondb (Steam/Valve's WINE derivative) write that the translated version (it's not an emulator, thus "translated") runs better than the native version. So it seems their Linux build isn't all that great. You might want to try with WINE for better results, even if this seems stupid at first glance.