A headset on older firmware can refuse to initialize.
It sounds cliché, but outdated drivers are a major source of VR instability. If your GPU driver is old, it may not recognize the VR compositor commands correctly. Steamvr Error 475
Steam has a built-in tool to remove problematic USB drivers. Base Station Channels:
Corrupted configuration files force false error readings. A headset on older firmware can refuse to initialize
Before troubleshooting, understand what triggers this problem:
If you are on a gaming laptop, you might also need to check the Windows Graphics settings:
Several issues can trigger this error: