Mathematica 12.3 won't launch. Freezes on 'opening welcome screen' and turns off.
Mathematica Kernel works properly.
Specifications: Version: 12.3.1 for Microsoft Windows (64-bit) (June 24, 2021) OperatingSystem: Windows 10 Home 20H2 ProcessorType: x86-64 Paclets: PacletManager Version 5.0.0
Mathematica worked correctly until two weeks ago. I don't think I installed any software that might obscure its functioning.
I tried deleting paclets, full reinstall (including and not including steps shown in: https://support.wolfram.com/12473)
Thank you for your help.