Used Mp3tag for ages on Windows 7 (and donated). Upgraded to Windows 10. Discovered that Mp3tag had disappeared from the Apps menu which only shows Mp3tag Help, Mp3tag website and Mp3tag version history. In the Windows 10 System Settings - Apps list Mp3tag appears as "Unavailable". So I downloaded the latest version of Mp3tag today (and donated again; this is a very useful app and worth paying for) and ran the .exe file. The installation appeared to run normally but then, as before, Mp3tag was missing from the Apps menu which only shows Mp3tag Help, Mp3tag website and Mp3tag version history. In the Windows 10 System Settings - Apps list Mp3tag appears as "Unavailable". So I ran the .exe installation file again as Administrator. Same result; in the Windows 10 System Settings - Apps list Mp3tag still appears as "Unavailable".
What now ?
P.S. Just discovered a partial solution. If I go into C:\Program Files (x86)\Mp3tag Mp3tag.exe is there with "date modified" 25-Jun-2016. I can right-click on that and tell it to "Pin to Start menu" so that I can fire it up by that route in future. However, Mp3tag is still missing from the Windows 10 Apps list and it is still listed as "Unavailable" in the Windows 10 Apps list in Setttings.