Well, it may be that older Canon DSLRs may no longer be supported (like HighSierra's 70D and my 30D). I can't install EOS Utility 3―not even available to me NADA!
I did update my version earlier this week. As I mentioned above: EOS Utility works ONLY if I unplug all my other usb devices (memory sticks & HDD). I tried uninstalling EVERYTHING and reinstalling, but as you well know, the update files will not REIN...