Logitech makes great PC accessories, and its latest flagship mouse, the MX Master 4, is a fantastic productivity device for PC and Mac users. However, all those keyboards, mice, webcams, and other devices require the Logitech Options+ app to operate properly and access all available customization. And right now, the app is broken on macOS.
The Options+ is a pretty controversial piece of software. Even though it is quite capable and powerful, stability issues and bugs are way too common. It does not take too long to find a frustrated post on Reddit complaining about the quality of Logitech software these days. And since non-gaming peripherals from Logitech have no onboard memory, there is no way to avoid Options or Options+.
To add insult to injury, Logitech appears to have forgotten to renew its security certificate on macOS. As a result, Mac users are now stuck with a dead app, non-working shortcuts, and other issues that they are unable to fix because Options+ simply cannot start (stuck at an endless spinner). Fortunately for PC users, the problem does not affect the app for Windows. Linux users are also alright, because Options+ is not even available there (there are some third-party alternatives, though), something that Logitech should fix, given that Linux is now getting much more attention than before.
If you have a Mac and you cannot run Logitech Options+, you have two options (get it?): wait for Logitech to wake up and update its certificate and the app or disable automatic date/time settings and roll back the date to January 5. This will bring the app back to life and let you use it until Logitech pushes a permanent fix.
Update: Logitech has released a fix, but you have to apply it manually. It requires downloading a patched version of the Logitech Options+ installer, which will then install a newer certificate.