The error code 108 on your HTC Vive headset occurs on the SteamVR app where it may not recognize the headset itself.
This may seemingly be a USB driver problem of sorts, and not much of an internal one.
But fixing it can be done in many ways. Just make sure to follow the steps below for you to be able to fix it immediately.
With that, here's how to fix the error code 108 on HTC Vive.
Fix the error code 108 on your HTC Vive by restarting your devices
In order to fix your HTC Vive's SteamVR error code 108, restarting your devices is highly advisable.
According to the official support page for SteamVR, you can either reboot your headset or restart your PC to solve it.
This is a basic way how to deal with internal issues on almost all kinds of gadgets and devices. So this might as well apply to your HTC Vive or PC.
Fix the error code 108 on your HTC Vive by adjusting some things on your link box
You can power cycle your link box to solve this issue.
Just unplug the power and USB cords from your link box and plug it again after a few seconds. Then open your SteamVR expectedly fixed by this point.
Alongside this, you can plug your link box onto a different USB port located on your PC. This might help to fix the error code 108 on your SteamVR app.
READ MORE: HTC Vive: How to use the camera