New version of the debug app for you to try. I'm sorry it seems like the progress is slow, but this looks to be something fundamental that I've always done and only now it is showing an error (for some systems).i always download the international nvidia drivers...
No need to run through the tick box options, just click start/stop and send me the nVidia.log file and post a video (please).
This version loads an initial texture...just to see if texture loading is an issue (which it looks to be) and adds some more debug tracing around that. I've tracked the area down to one of two possible functions...so hopefully the logs will decide which is the culprit.
The app can be downloaded from the Troubleshooting page.