I received the H501 error message after running a typical update of the software a month ago. Fortunately, I keep backups and was able to rollback the update to search out the source of the error. I'm not a computer expert, but I found the error was related to my running of the Win7 (x64) operating system.
Since many of the past updates didn't apply to me, my workaround was to (a) rollback the software to a non-error version and (b) disable the VIVE Updater program ("Updater.exe" found in the folder "C:\Program Files (x86)\VIVE\Updater"). It's just a workaround until I get either install Win10 or HTC decides to allow (even if they don't tech-support) Win7. I can't encourage you to do what I did, but it's been working for me for some time now, and no "update now" nag screens.
One final thought, I did contact tech support a couple times, as I was searching for answers, and was disappointed as (I believe) they feigned ignorance of what could be the cause of the error. I know enough about programming to know "someone" trapped that specific error in coding. I prefer if they would just be honest and say their latest update would no longer allow the software to run on Win7. Go even further and post an "Error H501" solution, if even just to say "It's Win7, install Win10". It's odd, but as of this writing, Win7 (SP1) is still noted as acceptable. Sorry if I sound cranky.
For what it's worth, I have a VIVE Cosmos Elite with hardwire cable to the computer. Graphics card and CPU are well above the minimums. And, I do love the Elite.
