I'm upgrading an instance of Portal for ArcGIS 10.8 to Portal for ArcGIS 10.8.1. It's been going on 3 hours and the installation is still not completed. I can see in Task Manager that there are some processes still working, such as OpenJDK Platform binary and Windows installer (32 bit). At various points the Portal for ArcGIS 10.8.1 Setup wizard has shown activity in the status bar, but it hasn't shown anything except Status: and an empty progress bar for at least 1/2 hour.
I've disabled Windows Defender real-time protection as I've seen it slow down installations significantly in the past.
And at about the 4-hour mark, I got the "Installer is no longer responding" error message, on which I clicked Reply.
Another thread here with similar issues:
OK. Well, after clicking Reply, the installation "finished" "successfully". Now when I attempt to connect to the Portal site, I get an ERR_CONNECTION_REFUSED. I also note that there is no Portal for ArcGIS service.
It looks like it maybe corrupted. No Portal service is not good. You can not run the Portal without it. Call ESRI support. If you have Premium support you should put the case there. Sorry to here this because I had to do a lot of work to get it back to 10.8. I hope you have VM snapshots of your servers with 10.8 installed.
I added you case number to my case. I hope to find more of these to show this to be something that needs to be looked at by ESRI in a very serious light. You can add my case number to your case as well. I will let you know of anything I get from ESRI that may help.