I don’t know if that can be influenced but I got this error when starting a Viveport app from Pimax Experience;
I tried to launch the same app again with Viveport already running in the background and it worked.
Even after closing Viveport the launch also worked.
I guess that the first launch ran into a timeout problem as it took to long to load Viveport.
After this Viveport files were still in cache so it did start faster so no timeout occured.