macOS Catalina 10.15.4 won't be installed on my Mac.

Verify what macOS you currently have installed

>About this mac

If you are running the 10.15.3 and need to update to the 10.15.4 you can download directly the

Combo update macOS 10.15.4 https://support.apple.com/kb/DL2037?locale=en_US

If you still have an issue installing this combo, reboot into SafeBoot Mode— then launch the combo installer from this environment.

SafeBoot https://support.apple.com/en-us/HT201262

Takes noticeable longer to get to the login screen, does a 5-15 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc. Login to proceed.

Solved!

From the install log, it noted a memory issue, so I pulled all 4 DIMMs and rearranged them. When I rebooted, the Catalina install process (from external USB) went perfect.

I hope this helps someone else.

Boot into Safe Mode and try the combo updater from there.

You need 20gig available space on the 2012-MID MacAIR!!! FYI ALL... its much much more than the 10+ gig requested at initial updated.

Check that you have enough storage.

I switched my wifi network and it worked. My husband had installed a new wifi since we both work from home, but for some reason it wouldn't allow the download. We still need to research it more, but I was able to finally get it installed. I need the iMac for my job. Good luck!

Don't send it, shipping might get it destroyed. While booting press command + r, if you have a backup, skip this step, go into the disk utility, plug in an external HD, take a backup. Format the disk, APFS format, not mac os jornaled. Close the disk utility, don't restart you mac here or you will have to install high Sierra. Click on reinstall mac os, ensure your Internet is connected, follow on screen steps, select your HD, and reboot back into mac os.

By the way I am installing the combo update instead of the system one, becuz mine dosent want to install, idk why. I have 50 gbs free on my ssd

Can you try to sign in as a root user, https://support.apple.com/en-in/HT204012, and in the safe mode, then try downloading the combo update again, and installing it again, it didnt work for me, even with system integrity protection off, even the "csrutil disable" command in command+r terminal didnt work, might work for you tho?

20gig avail?? no wonder why i cant update

To be honest I was fed up of trying so gained professional help and now it’s sorted. We ran onyx to tidy up. I deleted files apps email with large attachments. Sorted 😁

So, i had replied to this thread before, just wanted to give an update, i was able to remove the update files, for ~/library/update, but before doing that i had to disable system integrity protection, which i did and deleted the updates, freed up 5 gbs, totaling to the free space being 45 gbs. I downloaded the combo 1.15.4 update, but it still dosent work, it shows "Installation is completed". But it stil dosent install on a restart. By the way, i also have windows 10 with bootcamp (light gaming) installed on my air 2018. I think i will just take a backup of all the partitions using time machine and reinstall mac and windows, also it will clear out my space, and the clutter of files i have.

I tried the combo update yesterday and it didn't work. It's not a disk space issue. It downloaded okay, but when I tried installing it failed -- twice. If I click the update button on my system preferences, it does absolutely nothing; brings me back to the "update is available" screen.

I'm trying again now. Any other suggestions?

I had the same issue with 10.15.3 and to be honest i'm getting sick of this. I'm sick of wasting time trying to update my MAC which is only 2 years old. I carry out housekeeping on a regular basis. So Apple if you're trying to force us into replacing our MAC's you are barking up the wrong tree!!!

I am consistently advised that MacOS Catalina 10.15.4 will install on my MacBook Air tonight! Despite leaving my MacBook powered up overnight, it never does, and it will not install if I go for manual install during the day! My MacBook is currently running on macOS Catalina 10.15.3, so what is the problem?

I tried upgrading to MacOS 10.15.4 on my MacBook Air (2018). The installation stalled and now I’m unable to boot machine. I’ve tried the safe mode and holding down the control/option and shift before holding down the start button. System will not boot up - very frustrating. I called Apple care and they recommend I FedEx computer to be fixed.

Any thoughts on how to get the system to turn on without sendOmg machine to Apple care?

How does a upgrade cause the machine to stop working entirely?

Thanks in advanced for your thoughts.

Andrew