whats that? never saw that before:
on my diyplay option toolbar is a big red dot with the message:
ERROR: (material/GL32/beauty_primvertnorm_lit.prog) GLSL Shader failed to compile.

and nothin is diaplayed on the scene view. Already reinstalled HOU 18.5.496 but nothing...

Any Ideas?
And of course I have to finish a job today.... :-(

edit: installed the newest nvidia driver (496.13) before and I think thats the problem. reinstalled an older version (471.68) of the driver and it work again... wired...
Despite this would be a hint great...

It's also possible to fix this without rolling back your Game Ready Driver by installing NVIDIA's additional Studio Driver.

On the Geforce Experience 'Drivers' page click the 3 dots icon next to 'Check for Updates' and switch to 'Studio Driver'.

Installing this additional driver (which is more focused on giving the best performance for creative apps) fixed the issue for me.