System Instability after update

[thefrog]

you can see if this is relevant to your issue

Standard approach for fixing "Oh no! Something has gone wrong."?

Great that you got it working again! And yes, pacman is the package manager of choice on Arch based systems. It is the most reliable of all that I’ve used, and the only one supported by the Arch team. We have also yay (and paru) that are helpful with AUR software. Their usage is quite similar to pacman. Note that they can manage also native packages in addition to the AUR stuff.