Resolving Unknown Errors When Changing Device Mode in OpenVR Input Emulator

Introduction

OpenVR Input Emulator is a tool that extends SteamVR's input system. I encountered an error when attempting to assign the movement of a VIVE tracker to a VIVE controller.

First, I opened the settings page of OpenVR-InputEmulator in SteamVR.

Here, when I set Device Mode to Swap with and clicked Apply, the following message appeared:

Set Device Mode
Could not set device mode: Unknown error

Operating Environment

The error occurred under the following conditions:

• Windows 10 64bit
• SteamVR 1.2.10
• OpenVR Input Emulator 1.3

Investigation

I found a report of the same issue here:
https://github.com/matzman666/OpenVR-InputEmulator/issues/134

Following the link leads to this pull request:
https://github.com/matzman666/OpenVR-InputEmulator/pull/130

Apparently, applying a patch developed by volunteers to SteamVR resolves the issue. Note: This patch seems to be for Windows 10 64bit only.

Solution

Stop SteamVR

First, stop SteamVR if it's running! This is crucial!

Apply the Patch to SteamVR

Next, download and unzip driver_vrinputemulator_release_hopefully.zip mentioned in the pull request conversation.

Inside, there is a folder named driver_vrinputemulator, which should be placed in C:\Program Files (x86)\Steam\steamapps\common\SteamVR\drivers\driver_vrinputemulator.

Note: If you have changed the default installation location of SteamVR, adjust the placement accordingly.

If you have a folder named 00vrinputemulator directly under drivers, it should be removed. (Ensure to back it up just in case.)

Disable Safe Mode

Then, launch SteamVR. An alert appeared for me:

SteamVR in Safe Mode
Due to a recent crash, SteamVR is currently operating in safe mode. In this mode it will only load trusted drivers to avoid compatibility issues.

This indicates SteamVR started in safe mode because of a recent crash and is loading only trusted drivers to avoid issues.

In this state, the newly placed driver_vrinputemulator may not load correctly. Disable safe mode by clicking Disable Safe Mode in the dialog. This restarts SteamVR.

That's it for the process!

If It's Still Not Working...

It's possible that OpenVR-InputEmulator isn't installed correctly. In my case, keeping SteamVR running while installing OpenVR-InputEmulator caused it not to work properly.

After uninstalling OpenVR-InputEmulator, restarting my PC, stopping SteamVR, and reinstalling OpenVR-InputEmulator, it worked on my PC.

Conclusion

Thanks to the volunteers who created the patch, I was saved.