OpenVR failed to initialize (WMR)

[KRDucky]

Currently using Windows Mixed Reality and SteamVR. The API is OpenXR via WMR in the Steam VR settings menu. The VR application is Prepar3D. I can open the DesktopPlusUI program just fine but not DesktopPlus.exe. I am not using Steam.exe but instead the Standalone SteamVR install for offline installs on secured locations.

[elvissteinjr]

Desktop+ doesn't depend on Steam, though I've never tested it without Steam being installed (as opposed to Steam not running).
DesktopPlusUI.exe doesn't load OpenVR unless it detects DesktopPlus.exe running, in which case it'll also not open on the desktop unless forced via command-line argument (-DesktopMode).

Can you check the SteamVR logs? In a normal setup they're stored in the Steam log directory ("Steam\logs"), not sure where they'd typically end up on your system. Running "SteamVR\bin\win64\vrpathreg.exe" in a command line window would tell you the registered SteamVR paths if you don't know them yet.
"vrclient_DesktopPlus.txt" would be the most interesting log file, but maybe there's also something useful in "vrserver.txt".

The error code returned by VR_Init() not being displayed to the user here is a bit unfortunate in this case (managed to not be an issue so far though).
Do any other overlay apps work in your environment?

[KRDucky]

https://pastebin.com/Z9zxFWW9

Logs

[KRDucky]

we have a custom made addon for Prepar3D that works when it wants to. I am trying to find a better/more reliable alternative to the finicky addon. Our students use it for specifically mirroring their iPads with Mirroring360 to display their ForeFlight materials in the cockpit while in VR flight training.

[elvissteinjr]

Wed Sep 14 2022 13:58:47.642 - Failed to find interface 'IVROverlay_026'

If possible, please update your local copy of SteamVR. Running the latest version (stable or beta) is assumed by Valve, so I do the same. It wasn't explicitly mentioned because of this, but the last update of Desktop+ upgraded the OpenVR API library to use newer functionality (requiring the new interface).
If you can't, consider using an older release. Right now, anything except 2.7 uses an older OpenVR API library (mostly v1.12.5 from June 2020) and should work on older SteamVR versions.

I'll look into catching that error and displaying more meaningful messages to the user though. Thanks.

[KRDucky]

That seems to have done the trick. I now how to figure out how to show the overlay and get it to populate inside Prepar3D.