Photoshop will not load after upgrade today.

Try resetting the preferences.

To restore preferences quickly using a keyboard shortcut:

Press and hold Alt+Control+Shift (Windows) or Option+Command+Shift (Mac OS) as you start Photoshop. You are prompted to delete the current settings. The new preferences files are created the next time you start Photoshop.

Note: Using the keyboard shortcut, preference files for custom shortcuts, workspaces, and color settings will also be reset to default.

and update your graphics driver to the current studio (not gamer) version.

What’s your operating system version? What Photoshop version did you upgrade to? What specifically happens when Photoshop doesn’t load? Does Photoshop load if you revert to an earlier version: Creative Cloud app > Photoshop > 3-dot menu > Other Versions?