macOS Catalina 10.15.5 won't update on my 13" MacBook Air 2015

It's generally recommended to maintain a minimum of 20 GB of free space at all times to facilitate optimal system and application performance.

FWIW, I had the same issue updating from 10.15.3 > 10.15.4 a couple months ago on my Air 2013. I went through the same black progress bar > login screen progress bar and it ended up getting to the point where I couldn't login. Then I did force shutdowns, recovery mode, etc., and eventually nothing worked and I ended up with a brick. I'd try to delete the software update that's been downloaded and back off on updates going forward with an older laptop. Up until I had tried the update to 15.4 everything had been working completely fine, I'd had to free up some HD storage beforehand, but still, this literally killed my computer.

If I recall correctly, the install requires 18GB of space.

Having the exact same issue with my MBP 13" 2020 and seems unable to update no matter what I do, leaving it as it is for now, and having need to see the constant showing of update notification, which is frustrating.

I began a whole new discussion separate from this one for those of us with the mutual problem of update failure in spite of having more than sufficient space available... https://discussions.apple.com/thread/251578758

yes wipe a little more and try installing if not keep deleting, that the way i did it

I had the same problem. Downloading Combo update as I type.

But what with the already downloaded +4Gb update file from the auto MacOS updater? Is it deleted or how to delete it?

That's strange. It doesn't show in my System/Software Update preference pane, the Apple downloads site or the App Store. Where are you getting it?

In any case I'll wait for the Combo updater to be released on the Downloads site.

Since you are already on Catalina 10.15.xx, should be good for Security Updates for another 2 to 3 years. If you are asking if 2012 MacBook Air can upgrade beyond Catalina . . . Only Apple knows for sure.

Me, have Mac mini 2011 that can not go further than High Sierra 10.13.6, iMac Late 2012 on Catalina and do not expect to go any further. Also, 2018 Retina MacBook Air also on Catalina and expect to get one or two more upgrades 10.16 or 10.17 and end of the line.

Hope this answers the second question.

It makes total sense, thank you. Managed to update to Catalina 10.15.5 yayyy As for my MacBook Air 2012 I will wait and see. I also doubt it will be able to go beyond Catalina; however as long as Apple releases security only updates for it for another year or two I would be happy. My aim is to get 10 years out of it before I go ahead and buy a new MacBook Air. I think the new Macbok Air 2020 needs either one or two more refreshes before its really the best it can be ;)) Improved silent fans and a 1080HD FaceTime camera will make it a treasure haha

I can't install the Catalina 10.5.5 update either. I have a 2017 MacBook Pro with 138GB of space and when I try to install 10.15.5, I receive the message that it can't be installed on this volume:

I followed Mr. Phillips' advice to shut down and startup in Safe Mode before running the Combo Updater 10.15.5. Before I did this, I downloaded the 'non-combo' update and received the same screen warning message. Neither update is showing up in my Software Update System Prefs. Am I receiving this screen message because I'm currently running the OS 10.15 (19A558d) Beta? From what I've read, after I unenrolled from the Beta Program, the next regular release would just replace the Beta version. Do I need to use Time Machine to reinstall the last regular OS version or can I just download that and install?

Thanks in advance!

I am unable to update to the 10.15.5 version, plenty of room on my drive - nearly 90GB - and also tried to update in Safe Mode, all to no avail. The update appears to be going well up until when the countdown shows 2 minutes left, then it stops, and some 15 minutes later I get a message that the request has timed out. Does anyone have an inkling as to what might be going on please?

Hi Old Toad, it probably sat there for at the very least 10 minutes before the time out message popped up and the process was aborted - in other words, I didn't intentionally abort it myself, it just happened.

Booted in safe mode.

Downloaded 10.15.5 dmg.

Ran installer. Restarted in 10.15.4, but inexplicably still in safe mode.

Shut down manually, restarted manually. No longer in safe mode, still running 10.15.4. PLENTY of available space on HD (like 1 TB).

Any suggestions???

Because clearly there is a bug, which doesn't exactly inspire confidence. I'm de-activating automatic updates, taking out system preference from my doc and try to ignore all notification symbols. And certainly won't 'upgrade' my other computers to catalina. But thank you for your reply, you are probably the wrong addressee for my frustration over wasting time on something utterly insignificant.