OSX: MxMX cannot be opened because Apple cannot search for malware

If the MxMC 2.2 is installed on an Apple with OSX 10.13.6 or higher, the following error message may appear.

In this case, the OSX security settings can be temporarily adjusted to allow the MxMC installation.
To do so, please use the “Security” menu item under OSX Settings to allow the installation of applications “from anywhere”.

If this setting “from anywhere” does not exist (sh Screenhot before) then please enter the following command as “Admin” user in the Terminal window of your Mac

sudo spctl --master-disable

this adds the item “from anywhere” to the menu. (Further instructions are available under
https://www.tutonaut.de/anleitung-gatekeeper-auf-dem-mac-umgehen/ to find)

Then reinstall the MxMC