macOS Catalina Update 10.15.3 available - installation recommended and completed successfully!

macOS 10.15.3 update for Catalina

I usually don't write a separate blog article for every little macOS update. But since there are still many problem reports from readers who have massive problems with macOS Catalina (see here in the Catalina Problems & Solutions collective contribution), I just wanted to bring you the good news that Apple has released another bug fix update.

The update to 10.15.3 is primarily aimed at fixing bugs that unfortunately came to the Mac in large numbers with macOS Catalina.

The update to 10.15.3 is primarily aimed at fixing bugs that unfortunately came to the Mac in large numbers with macOS Catalina.

My recommendation: Install, macOS-10-15-3- possibly with a backup

I always install such small updates without a separate backup, because I always have a reasonably current version of my system somewhere on an external hard drive. As a rule, such point updates only make the system more stable and no new problems arise.

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However, due to the fact that many people seem to live completely without a backup, in this case too I would like one with a program like SuperDuper, SmartBackup or Carbon Copy Cloner create - it doesn't do any harm and in case of doubt you can quickly fall back on a version before the update. And with macOS Catalina, Apple has not exactly ensured that the user community has more confidence in the reliability of the system.

10.15.3 brings these innovations

Here I am simply quoting from the release note of the update, because unfortunately Apple does not yet have an entry for the update on your List of security updates made - accordingly the details of this update are missing.

macOS 10.15.3 update –– restart required

The macOS Catalina 10.15.3 update improves the stability and reliability of your Mac. It is recommended for all users.

This update:

  • optimizes the gamma handling for weak gray tones when working with Pro Display XDR for SDR under macOS and
  • improves multi-stream video editing performance for HEVC and H.264 encoded 4K video on the 16 ″ MacBook Pro (2019).

At first glance, there is little to see here, because both points only affect a small target group, but one can assume that Apple has ironed out other errors with the update. Bugs that users mention are not always publicly acknowledged by Apple, but luckily they are still fixed in the background at some point.

The update to Catalina 10.15.3 did not cause any irregularities in my case.

The update to Catalina 10.15.3 did not cause any irregularities in my case.

Update: The security update was successful

I just performed the update on myself. The installation took a good 30 to 45 minutes, which I found to be quite long, but after that the Mac rebooted cleanly. As far as I can see everything is going as it was before. On my part, there is no reason to advise against the update.

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  1. Marty Shellman says:

    So I would be careful! At Catalina, a little waiting is always my motto. Regarding 10.15.3, I've read the following two rather bad support posts.

    Random freezes and restarts:

    Loss of performance:

    • sir appleot says:

      Ok, they both concern the 16 inch model of the MBP. I think you should be careful anyway, because the hardware is still quite "fresh" here. If in doubt, make a backup. Then not much can go wrong. But thank you for your advice!

  2. Ludger Rieger says:

    The update to 10.15.3 is downloaded for me, at the end I should restart and then the message that the update to 10.15.3 is available comes up again when booting. My macmini 2012 is not updated at all when it starts up, but the system simply restarts. On another device (macmini 2014) the installation took a long time.

    • sir appleot says:

      Hello Ludger! You can usually find the Catalina installation file in the "Applications" folder. Maybe restart it manually. Then he should actually start installing. It is quite normal that the installation takes 1-2 hours - and maybe even longer on an older Mac without an SSD and Fusion Drive. Even the update to 10.15.3 took me almost an hour yesterday. : D

  3. Wolfgang Mouse says:

    Dear Sir Apfelot,
    an old dumb Mac user has a few questions again.
    For brief information, I am attaching 2 screenshots.
    Now a question: Can I update to Catalina without any problems and, for example, continue to use my FinalCut ProX as usual?
    Second question: I downloaded the security update for Mojave. How can I install that? Got the dmg on my desk. What do i do now Unfortunately, my supportive help lets me down a bit. It used to be that you just had to drag everything into a folder and then everything was in the right place.
    Would be very grateful for help, Wolfgang Maus

    Can't attach the info pictures. Another relaxing weekend

    • sir appleot says:

      Hello Wolfgang! I am happy to help even without the two screenshots. : D
      First question: Upgrading to Catalina "without problems" is a very vague thing. There were no problems with me, but as you can see from the collective contribution for Catalina problems, quite a lot of people had problems with the upgrade. For this reason I would recommend using SmartBackup or something like that to make a 1: 1 copy of the system on an external hard drive and then give Catalina a chance. It is impossible to predict whether you will have any problems or not. For this reason, I would always assume the worst and make a backup.

      Regarding the second question: You just have to double-click the DMG. Then it mounts itself like a "virtual" hard drive and you see it as a volume. You can then take a look through the Finder window and you should find a file in this volume that installs the update. Simply double-click this file.

      Have a nice weekend, too!

  4. Mircinho says:

    Anyone who, like me, connects their macbookpro via the landing zone docking station to two external monitors via HDMI ports should avoid the update as much as possible, as only one external monitor is recognized after the update. I have the salad now ...

    If anyone knows a solution to the problem, I would be very grateful ...

  5. Paul says:

    Hello, my update hangs up permanently. MacBook Air mid-2013 I restarted several times and the update kept hanging with a remaining time of 5 minutes.
    Can I cancel the update?

    • sir appleot says:

      Hello Paul! Sounds strange ... Aborting updates is always critical. I would let it run for another 1-2 hours and then turn it off when nothing happens.

      • Paul says:

        Thank you for your answer, I've already tried it twice over night. Stops again and again, switching off already tried, starts from the beginning and stops again at 5 minutes. I already tried to restart Cmd + R with Cmd + L, unfortunately the update always starts.
        Is there a way to cancel the update?

  6. Martin Gunther says:

    Hello, I have a UMC404HD USB sound card from Behringer. After updating to 10.15.3 I have permanent sound dropouts. Does anyone know the problem? This was not the case with 10.15.2 - as far as I know the UMC uses the core drivers from Apple - means that the problem must lie here.
    Thanks for info ...
    Regards, Martin

    • sir appleot says:

      Hello Martin! Unfortunately, I have no idea what to do there. I guess to downgrade again and wait for 10.15.4. Or ask Behringer. They will surely have a tip. :-(

  7. Stange says:

    Unfortunately, I have the problem with Catalina that I can no longer log into iCloud. I can no longer use my apps except for Safari.

    • sir appleot says:

      Hello rod! Restart your Mac, install Catalina over it and start in Safe Mode already tried? If so: What exactly does the error message report?

      • Ms. Stange says:

        An unknown error has occurred

        • sir appleot says:

          In this case I would try the following: Turn off the Mac and then log into iCloud via iPhone or another Mac. Then under Settings> My Devices, eject / delete the Mac with the error from the list (blue X next to the name).
          Now reboot the problematic Mac and try to set up iCloud again. Does it work?

  8. Edith Kirchhofer says:

    Unfortunately, with Catalina, I have big problems with my iMac. I called the Apple hotline several times in this regard. Sometimes there are very incompetent employees.
    The language barrier is also a big problem. They said to me I had to speak more standard German. ???

    • sir appleot says:

      Hello Edith! If you like, you are welcome to explain your problems here. I'll try to help you then. Will work despite the language barrier ... I'm sure of that. : D

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