SteamVR Sandboxing, Black screen on headset

[The-personified-devil]

This issue describes the black issue caused by SteamVR sandboxing. Other causes of the black screen issue are also covered on the troubleshooting page though.
Reference workaround for this issue: https://github.com/alvr-org/ALVR/wiki/Linux-Troubleshooting

The black screen issue is caused by a component of SteamVR called vrcompositor running in the Steam Linux Runtime Scout (SLR 1) sandbox, which we can't compile our vulkan layer for. The workaround solves this by partly disabling the sandbox. The workaround is always needed to fix this issue. This is a known issue, please don't report it again.

NOTE: The vulkan layer is needed because SteamVR doesn't expose internal information related to rendering, so the vulkan layer intercepts it for us. An api to solve this called direct mode has been exposed by SteamVR, but it has a bug that makes it unusable currently. Once a fix is shipped we'll use this api, rendering the workaround redundant.

[Espionage724]

Would this happen to affect Windows over USB, particularly a few days ago and with SteamVR beta?

I have a Quest 2 and with ALVR (sideloaded nightly or App Lab), using wifi as-is was fine, but after the USB forwarding commands and trying USB, ALVR in the headset would render nothing (black screen).

Edit: Yep I forgot to set TCP; that solved that fine

[Vixea]

Nope its specific to Linux

[The-personified-devil]

@Espionage724 that sounds like you forgot to set the stream to tcp