Windows 10 update (v1909 I think) broke Quake Live, making it nearly impossible to get the game to load through Steam. If it did load, it played normally, but getting that far was the trick.
In the unlikely chance there is anybody besides me still playing this game...
The very latest Windows 10 update (v2004, I think) released just a few days ago fixes it. You can force an update manually if you are really desperate for your Quake Live fix. I am a really serious gamer -- I have
three whole games on my computer: DOOM, Quake III Arena, and Quake Live. Hey, they were good 20 years ago, they still are now!
tanstaafl.