Safari cannot start after Big Sur update to version 11.6.5

My computer updated MacOS Big Sur from 11.6.4 to 11.6.5 yesterday. From that point on, Safari cannot be started. When I launch it directly from the Dock, the icon jumps once and then rests with no effect. When I try clicking a link in Notepad to open Safari that way, I get the dialog box saying "the application Safari.app can't be opened. -1":

I am checking processes and Safari is NOT running.

In addition to this, the MacOS Mail application cannot login into my Gmail accounts any more. The accounts are offline and when I click them to go online, a dialog box asks to provide a password. When I click it, it opens an empty window, which is obviously dependent on Safari:

The window has rotating icon and never progresses anywhere.

Bottomline: Safari is completely disabled by the Big Sur update 11.6.5, which also disabled parts of Mail operation.

My computer is MacBook Pro, 15-inch, 2017, 2.9 GHz Quad-Core Intel Core i7, 16GB RAM.

I would appreciate if someone who found the fix could share.

Thank you!

Evgenii