Problem with MacOS update 10.15.7 2020-001

The thread concerns a problem with private users of Catalina not people on networks running basic OS routines., these systems are fixed, they have back ups and this is what i also found to be the solution for private users, there is no real fix, back up daily clones and be ready to restore.

As for Apple been linked to big tech abuses that is Tim Cook’s job to deal with, i met Jobs back in the early 90s, during a period he was not with Apple, we are not seen the vision he had then of walking into a coffee shop that has a tables with builtin screens ready to load your user profile from a cloud via an apple watch, we are apparently seen a market growth intervention, many political interventions, Apple is bigger then the government, all over the world, on a world stage now and China who provides parts and assembles products are not just a tech competition, so i dont think Steve anticipated what Tim Cook is now facing.

i do have an ipad 2 with system it shipped on it and its as fast as my ipad pro, but i cant run the same apps, i refuse to jail break it as i learned others did to run newer apps, poorly, regardless of this some how we will all have to accept moving on..

solution again is cloning your catalina drive on regular basis

I know SuperDuper since early times, it did always a fantastic job for me. Used CCC, too. All the old app, so the sis nothing new to me ;-) When time machine came, I worked with several backup strategies parallel, to see if it' stable (never change a winning team). Any ´way, I had never a prob with time machine, hope it stays like this.

Anyway, all what's written in the blog post is nothing new, Data Volume and system volume that's kind off the deal with the new AFPS, yes, come on, why not? If it works. And it seems to work for lots of users, including me, beside of this security update stuff I never had a problem before, It would be interesting to investigate in this. There must have been something like firmware update included in this security patch, mainly something about the USB busses, what would explain the described problem.

Cause it's not to be explained, why everything ran stable before (with Catalina fresh installed on external disk), hundreds of restarts shutdowns etc, no single prob, Security update - bang. And even while on my ext volume its again a fresh system installed (I deleted the whole disk entirely), there seems be something written wherever...

Honestly, I'm wondering about that SuperDuper still does exist, nice to know although they should really go with the times, too, and update their website, We know that's it was a great software, but if I would come as a new user now...: Sorry, that doesn't look like a reliable source for something critical like Backup Software know what I mean?

But of course, don't get me wrong, this ist nothing about the work of the guy(s) and their software. Just my 2 cents ;-)

I can confirm that something got "clobbered" in the boot rom -- I can't boot from either an external SSD (Catalina), nor an external SSD (Mojave).

Both of these SSDs work on an non-updated iMac.

VARanger1: Are you booting from the internal drive or an external drive? Also, is the internal drive original to your iMac, or did you replace it at some time in the past?

No solution either, but reports start to pop up: Obviously we're not alone with this strange, erratic behavior:

https://forums.macrumors.com/threads/security-update-2020-001-for-10-15-7.2275352/post-29397181

...further update.

I can't seem to boot into Recovery Mode on the affected iMac either. It will startup from the internal HD (Mojave), but completely ignores requests to boot into either local Recovery Mode or Internet Recovery Mode.

UPDATE:

Update was installed, but external SSD still not working as a startup disk!

I was hoping completing the update would bring boot to normality - which is not the case.

The Mac keeps loading the internal drive, now having to target SSD on every startup.

Apple, please fix this!!

you guys all dont seem to understand, Catalina is stated to support MacBook Pros from late 2012 and up, how ever Apple does not mention how they drop support for machines upon updates and which once to warn people in advance, in fact they drop support for certain components (hard drives, airport cards, bluetooth boards and once you update there is no chance of reverting, your whole system and files will become encrypted and invisible from the finder until you finish this update or you will have to erase everything.

This causes allot of paranoia, you have people angry at not been able to repair this on machines which Catalina bricked the power boards lowering their ability to work beyond 5v where users only see a black screen, and there is no way to finish the update on apple servers as the EFI files will be missing, so while you think your machine works and maybe can avoid future updates there are also apps you may end up installing that won't work.

I just wish apple told people which updates will not support which machines.

I had to mention this, i have 10.15.7 installed on my macbook pro, yet whenever i get login security notification from websites like google, paypal etc the OS version varries, example PayPal now says i used Desktop Safari OS X 10.15.6. 🙄

Very messy business guys

Here is the workaround that is working for me:

1. Shut down your iMac
2. Before turning it back on, unplug all other external drives from your iMac except for your external drive that you boot from. Leave this one plugged in.
3. Turn on your iMac.
4. After the iMac boots up, plug your other external drives back in.
5. Everything should work now.

This isn’t an ideal solution but it works for now, and hopefully Apple will fix this issue soon.

None of the methods you guys are talking about should work or at-least do so sustainably,

Not just EFI issues, its designed to NOT work with parts Apple did not ship computer with,

There is a secret though, Any drives catalina fails to see and wont get repaired by disk tools can using a ipad pro and a camera kit, once you connect any hd this way pados will refresh the devices used making them readable by catalina again., so you can continue an update, upgrade or successfully mount a bootable hd., try it before erasing a drive, this is the same with macbook motherboards with soldered drives bricked by Catalina.

I don’t want to ruin your days but Catalina will put you right back to not booting to the external SSD. You can expect to receive a message stating your external drive was disconnected incorrectly. And you will be back to internal Drive only. Just wait for it. I’m convince it is related to an EFI partition bug in Catalina. A simple reformat and reinstalling will not solve the boot up either. Many hours wasted trying to solve this problem.

exactly what I have been trying to say,

You can run disk tools and literally see the EFI error while its up and running,

the only way to update these EFI firmware is by connecting the drive to a iPad Pro using usb camera kit, I noticed this been done at a 3rd party apple reseller store (they had no idea I could see them lol) and I tried it myself and got a 8tb drive mounted on both my iPad Pro and cpu, I guess apple is ok with the idea you guy a MacBook Pro and usb camera kit just to sort your drive issues, they cant do anything around this or their iPads can not utilise drives....I guess by the time its fully supported and or unblocked we won't have MacBooks or iMacs anymore., this is about--> $$$$$

Not into conspiracy theories, but believe you are correct. This about money, and another action by Apple to control you Apple devices and create a fatal disease for your older, reliable, durable, up grade able, Apple product. Apple wants my 2013 iMac in the trash bin and replaced with their new lease me Apple products. This is a dispute over who owns your Apple products.