It looks like I have to update the OS on my old machine to use TeamViewer, else I can’t remote to my clients for a week.
I looked on my backups and I have the Mountain Lion install (currently running SL on a 2008 unibody).
I have 3 copies of this install, and none will run. They all say they are damaged and that I need to download again. It directs me to the App Store, where I do see ML way down at the bottom.
However, I know I also downloaded Sierra and High Sierra, but they are not on the list at all.
First question - how can I protect the downloads I have so they continue to run?
Second - where did my Sierra installs disappear to? I do have backups of those too but now I’m afraid they won’t work if I ever need them.