Chapter in this post:
Like every year, yesterday I jumped at the new macOS update with joy so that I could try it out on my MacBook Pro as quickly as possible. Unfortunately, the download of macOS Big Sur dragged on like chewing gum and at some point broke off completely.
A repeated initiation of the update showed a rapidly growing progress bar, but then it stopped again. After a few minutes of delay, the following error message appeared:
Installation failed. There was an error installing the selected updates. [OK]
Thanks for this informative error description ...
So far the mistake wouldn't have been tragic, but unfortunately it persisted. As soon as I started the update again, the Mac stopped with the above-mentioned "Installation failed" message.
I thought a reboot should fix the problem, but in this case even this miracle cure failed IT Crowd. Even after a complete cleaning run with my favorite make-up program Clean My Mac X the error message was there again.
Another idea was to cheat the Mac with the key combination CMD + ALT + R at system start, because this will install the latest macOS on the Mac that is still running on the device. In my case, that would theoretically have been macOS Big Sur, but unfortunately the recovery only suggested Catalina to me. I suspect because Big Sur is not yet known as a recovery system on my Mac. Anyway, the path was also a dead end.
Ultimately, the following procedure brought improvement: I called the recovery mode with the key combination CMD + R when booting. In its menu you will find the item "Reinstall macOS", which I have chosen.
This installed macOS Catalina again over my existing Catalina, which took almost 1,5 hours. I went to sleep in between.
When I brought the Mac out of hibernation the next morning, Catalina's login screen was visible and a click on the refresh button started the download of macOS Big Sur again. This time with success, because the bar ran through completely and the Big Sur installer appeared.
At this point I quickly dragged the “macOS Big Sur Installer” in the Applications folder onto my external hard drive so that I had it ready for future actions. But you can also get started right away and install the system.
After all this action, I am running macOS Big Sur - and it is very stable. I can't complain!
Perhaps the instructions will help one or the other who also sees this error message. Often it doesn't seem to happen, but if it hits someone, they may be happy about this post.
Jens has been running the blog since 2012. He appears as Sir Apfelot for his readers and helps them with problems of a technical nature. In his free time he drives electric unicycles, takes photos (preferably with his iPhone, of course), climbs around in the Hessian mountains or hikes with the family. His articles deal with Apple products, news from the world of drones or solutions for current bugs.