Security Update 2020-001 (Catalina) download error

I have not been using my late 2012 Mac mini much lately and today tried to install Security Update 2020-001 (Catalina) . The download failed multiple times after nearly finishing. I copied the final entries from the Console Installer log and can provide if that would be helpful.

Because I hadn’t used the mini much it showed three updates when I logged in this morning.

Safari 14.01

Safari 14.02

Security Update 2020-001 10.15.7

I assumed that update 14.02 update for Safari would include all patches in 14.01, so I selected just that update to install first. It seemed to install OK. Then I selected just Security Update 2020-001 10.15.7 to install. This file seemed to be downloading OK and I did other stuff while it loaded. It was getting nearly complete when the download meter said the file had completely downloaded all 1.32 GB. I watched and waited for the install to begin, but nothing happened. Then I noticed the Process “softwareupdate” was still chugging away and was over 1.6 GB downloaded, well beyond the 1.32 GB file size.

After half an hour of nothing happening I restarted. I went back to Software Update and again selected Security Update 2020-001 10.15.7 and clicked “DOWNLOAD AND RESTART”. The download meter quickly ramped up to over 1 GB already downloaded and estimated there was 12 minutes to completion. A few minutes later the onscreen window showed the entire file had been downloaded but nothing happened

As I mentioned above, I copied the final entries of the Console installer Log about where it showed “Error Domain=PKDownloadError Code=14 "(null)"). Retrying for attempt #1.“.

Another oddity, while the file had started downloading for when third time I noticed that the total number for Received Bytes would suddenly get smaller. I’ve never seen that value get smaller before, except after a restart when it is reset to zero.

Appreciate any guidance on what I should do next. I wonder if installing Safari 14.0.2 first caused a problem for the security update? I also found an installer at https://support.apple.com/kb/DL2067?viewlocale=en_US&locale=en_US and wondered if this might be successful where Software Update wasn’t.

Eric

P.S. this support page only offers Mac mini 2018 or later, there is no selection for earlier models of the Mac mini.