If you're having problems with QTTabBar, you can try the open source alternative ‘Tablacus Explorer’. This software is very similar to QTTabBar.
See screenshot:
Tablacus Explorer Download
GitHub Tablacus Explorer
Yes, I had the same problem today, but thanks to a restore point, I was able to restore my Windows to 30 November. Now Qtabbar is working again. I paused Windows Update for 5 weeks.