The Minecraft launcher will not work.

Whenever you click the Microsoft Login tab, the following message appears in the top right:

Something went wrong in the login process 

We have reinstalled the Minecraft from the server multiple times. We have cleared the system of any remnant of the old installs.

This does not have anything to do with Minecraft versions, since the launcher never gets that far.

Our launcher says that it is 10.36

We are running on a quite old Mac Pro - early 2008, dual quad core with 20GB ram. Everything has run perfectly well before this.