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

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.

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.

I managed to get it to install in the end: after the umpteenth failed attempt I recalled someone in some post somewhere stating that the update had to be helped along by "jolting" the system shutting it down with the power button straight after a failed attempt. To my surprise it did work, one more try and the update went through!

13 GB wasn't enough free space to allow the install. I tried again once I had 73 GB free. Maybe that's what was required, or maybe they updated the installer version by the time I gave it one more go.

It's generally recommended around here to try to maintain a minimum of 20 GB of free space to facilitate optimal system and application performance. More if possible. This allows room for temp system, swap and cache files as well as letting new files be saved more less unfractured which will greatly help is speed of opening and saving.

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.

What bug are you referring to? How much free space do you have on your boot drive?

Since this is just a user to user forum we're here to try to solve problems not listen to rants.

You should remember judging an update by what you read here is like judging the health of a city by what you observe none of its hospital's emergency rooms.

I think it's a bug if an update does not know how much space it needs for an update and/or does not inform the user that it does not have enough space, and just keeps going around in circles, each time wasting the user's time.

If other users say that 1TB is enough I am not going to waste my time in deleting data I need on my drive.

And yes, I would actually judge the health of a city by a hospital's emergency room, especially in these times.

At attempt to install 10.15.5 from the App Store by clicking the "Get" button redirects me immediately to System Update in System Preferences. Since I have already tried to install from there multiple time with no success I abandoned that process. I then did a search for 'recovery' in Finder and no such match for 'Reinstall MacOS' exists on my system apparently. Any other guidance or help here would be greatly appreciated. Thx!

When I attempt to update in Safe Mode using the App Store and get the error... Is there a way to determine which error occurred with a code to identify and troubleshoot from? Not knowing what error occurred is of no help.

I was facing the same problem for the last 3 days since this update came.

1) I downloaded the O/S update and it was showing 2.98 gb and it was showing That I still have 8 to 9 gb of space left in my MAC.

2) As I pushed the update button the screen would blackout and then apple logo and restart.

3) on restarting I found its still not installed. I repeated the process several times but the results were same.

Here is what I did to successfully install it.

1) I deleted some old movies and videos to create a space of around 15 gb on my MAC.

2) Restarted and then started the installation process.

3) It took around 20 mins to install this new update. and screen going as Macintosh update will take nearly 37 mins, 9 mins more and so on. Until it installed fully.

So try it. I just explained the steps so that you don't get frustrated with the time it shows for installing an update.

I faced the same problem and the Safe Boot + Combo Update trick didn't help.

Check if you don't have a too much "OS-intrusive" software.

In my case, I had to uninstall Cisco AnyConnect. Update worked fine then even from System Preferences.

Check if you don't have a too much "OS-intrusive" software.

I had to uninstall Cisco AnyConnect. Update worked fine then even from System Preferences.

Sorry for the double post, don't know how to delete previous one :(