I get the following message after downloading and trying to install macOS Big Sur: "Installation failed. An error occurred while installing the selected updates." I am trying to upgrade a Mac Mini late 2014. Any suggestions?
It appears you had Avast AV installed at some point and did not properly uninstall it so it has left behind some pieces that I suspect are causing your problem. You need to completely remove Avast, you can either re-install Avast and then use the developers uninstall app to properly uninstall or use FindAnyFile to locate anything with the word "Avast" in it (which I hope would get rid of all of Avast) or you last alternative is to do and erase and install and start over again.
It appears you had Avast AV installed at some point and did not properly uninstall it so it has left behind some pieces that I suspect are causing your problem. You need to completely remove Avast, you can either re-install Avast and then use the developers uninstall app to properly uninstall or use FindAnyFile to locate anything with the word "Avast" in it (which I hope would get rid of all of Avast) or you last alternative is to do and erase and install and start over again.
Please restart in Safe Mode and then restart normally and re-test. If the install will not complete, please do the following:
Please navigate to the Mac App Store or navigate to www.Etrecheck.com and download the free version of EtreCheck. Once you have you downloaded the app and installed it, please run the report and save it. This report will help us get a good idea what has been installed on your system and help us be able to diagnose what may be wrong.
When you have your report, you can attach it when you reply to this message and we can then review it and help you determine what is needed to get your system running well again.
For instructions on how to download your EtreCheck report and attach it to your reply to this message please click https://discussions.apple.com/docs/DOC-250000211
Before you try again, by chance do you have any third party antivirus, security or cleaning apps installed?
Please try at a later time.
I tried early this morning and then again around noon. Failed both times. How long should I wait before trying again?
My install ran completely without a hitch, last night, about 6pm Cupertino time, BobDeG54.
Since this is a “Global Phenomenon”, good times will vary!
Ah ha, I am running Avast! Will try uninstalling before trying again. Thanks for the suggestion.
Unfortunately, after uninstalling Avast and restarting the computer, still no luck.
Thanks for your help! Restarting in Safe Mode and then restarting normally did not resolve the problem. I followed your advice to download EtreCheck and here are the results of the EtreCheck report.
Avast and all other 3rd party AV apps are 100% worthless and should be uninstalled per the developers instructions. If you want a slow, unstable, buggy Mac experience please keep it installed. Avast, like all third party AV, Security and cleaning apps offers NO additional layer of security.
The BEST antivirus, cleaning, security and overall maintenance app for Mac OS is Mac OS itself. If simply left alone and kept up-to-date Mac OS will run securely & reliably for most users for many years. In over 20 years of ownership I have NEVER installed any these apps and have never experienced any problems.
"Installation failed." Can't upgrade a Mac Mini late 2014 to macOS Big Sur...
