For some reason Safari is damaged in my Mojave installation. It seems reinstalling Mac OSX might fix it, it is causing my system to reboot randomly. The GPU that came with my 4,1 system (upgraded to 5,1) is a 4870 which is not METAL compatible, so I don't think I would be able to reinstall Mojave by putting the card back in the system, pressing command+R and choosing to reinstall OSX from the boot up menu. I can however try reinstalling Mojave from within my existing Mojave installation, should I try this?