Stopped working after the last SteamVR update

[KageDev]

Deleting all the dll files and verifying integrity isn't working - after installing the mod, the SteamVR stops launching.

[Oricul]

Restore your original DLLs (if you haven't already, or just delete them out-right). Verify SteamVR integrity. Re-install WMR_vrclient.

Had to do this myself and those are the steps I used.

I just re-read your post, noting that you deleted and verified (hopefully in that order). Delete the files, verify and test SteamVR without the mod first. If it works, download the latest version of the mod and try again.