I've been a longtime user of the genealogy software Reunion for the Mac. I haven't upgraded it in a while (still had version 9). When I went to look something up today, I was informed by MacOS HS that I needed to upgrade as the version I had was not optimised for use on the current (and one presumes future) MacOS. While the program worked just fine, I bit the bullet and upgraded to the latest version. That took care of the system prompt, now all I've got to do is get used to the newer interface and fix some broken links in my database. I would guess that I am going to see these prompts on other software I have that is aged out, soon enough.