In Unity, I ran into this issue when attempting to set the backend to OpenXR using the Oculus Utilities from the Oculus Integration v53.1 (stating my version here just in case it doesn't work on another version).

Every time I would click Oculus > Tools > OVR Utilities Plugin > Set OVRPPlugin to OpenXR I would get this error:

Unable to Activate OVRPlugin with OpenXR: Oculus Utilities Plugin package not activated

Discovery

I tried to reimport the whole Oculus Integration but unfortunately that didn't fix it. I couldn't find anything else online about this error, hence the blog post, so I decided to do some digging into their code. I found out that this error came from line 710/711 in Assets\Oculus\VR\Editor\OVRPluginUpdater.cs. I added a breakpoint, attached it to Unity and ran it again to see what file it was looking for. I discovered it was looking for Assets\Oculus\VR\Plugins\1.85.0\AndroidOpenXR\OVRPlugin.aar but my file was disabled (...\OVRPlugin.aar.disabled) and therefore throwing that error.

The fix

All I had to do was rename the file from OVRPlugin.aar.disabled to OVRPlugin.aar, then click Set OVRPlugin to OpenXR again and restart my editor! I'm not sure why it was disabled but it hasn't caused any issues for me since enabling it. Make sure to backup anything you don't want to lose just in case, I usually make a complete duplicate backup project before messing with anything like this.

Potentially relevant details

• Unity 2020.3.36

• OpenXR 1.5.3

• Oculus Integration v53.1