This error means that the 64bit vorpX injector is missing. If you didn’t delete it yourself, it probably was removed by some overzealous virus scanner. Reinstalling is the only way to fix this.
Might make sense exclude the vorpX program folder from your AV scanner before reinstalling.
I’m very meticulous with excluding non game exe services and processes.
The other thing is I only use windows defender and certainly didn’t delete the 64 bit version. I am using a pimax but correct me if I’m wrong all openvr hmd are seen as the same thing?