How to stop the screen from flashing? I recently upgraded to macOS Catalina. I use a setup with Karabiner Elements and Hammerspoon, so I can switch between apps using shortcuts like Caps-Lock+Letter.

My caps-lock is configured to act as a 'Hyper' key when held down, meaning its the same as pressing command + option + control + shift.

However after Catalina upgrade, whenever I press caps-lock + W, the screen flashes.

It also happens when I press the keys individually, so command + control + option + shift + W, so I believe it is some new shortcut introduced in Catalina that does this.

However I can't seem to find what it is and how to disable it, could anybody please help?

The flash is the same as the flash you see when you go to System Preferences &gt; Accessibility &gt; Audio &gt; Test Screen Flash.
WiFi Diagnostics Keyboard Shortcut in macOS Catalina

It looks like cmd+ctrl+option+shift+w triggers a WiFi Diagnostics session.

Browse to /Private/var/tmp and you'll see 300MB+ files titled WiFiDiagnostics_YYYY-MM-DD_IP4-address_Mac OS X_MacModelName.tgz

I can't find any official documentation on this, and I believe this is new for Catalina.