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"BAD MAGIC! (flag set in iBoot panic header)" — Catalina freezing all the time!

I formatted my Mac and reinstalled macOS, the solution I was hoping to frequent freezing (after about 30 minutes of normal use). To my terrible surprise, my Mac still froze. A hard shutdown and restart and here I am.


The log says this: "BAD MAGIC! (flag set in iBoot panic header), no macOS panic log available"


I'm at a loss. I haven't installed any software and it froze. A quick hardware diagnostics didn't find anything wrong with my hardware. This is a new 2018 MacBook Pro. It was working great until Catalina.


This is terrible. I place myself in the helpful hands of the internet in the hopes of solving this.

MacBook Pro 15”, macOS 10.15

Posted on Nov 5, 2019 6:04 PM

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Posted on Apr 18, 2020 8:32 AM

I have the same issue. Happened within the first week of owning my new 16" MBP. I asked an Apple tech at the store about the error (BAD MAGIC! (flag set in iBoot panic header), no macOS panic log available) and he said he'd never heard of it.


Just happened again for the 2nd time. Computer is less than 2 months old. Very disappointing.


414 replies

Sep 2, 2020 11:14 PM in response to pedro-ale

Hi together,


yesterday i had the same issue again. But running on MacOS 10.15.6.

I guess this issue is renamed to "x86 CPU CATERR detected" (See my new Thread: https://discussions.apple.com/thread/251755817)


You can find exacty the same Bad-Magic message in the "macOSPanicString" of the Kernel-Panic log.


So do you think i need to replace my hardware?

Dec 29, 2019 8:58 AM in response to pedro-ale

I was experiencing the bad magic issue just like everyone else.


Issue I had:


  1. When computer was connected to two monitors, it would restart and produced a "bad magic" error.
  2. If I left the lid open with the two monitors connected, nothing happened. (Keep in mind the power cord was left connected)
  3. If I closed the lid and left the two monitor connected, computer would crash. (keep in mind the power cord was left connected)


My issue was only persistent when ONLY two monitors were connected. Nothing would happen when the monitors were unplugged.


2018 MBP Touch Bar 512gb SSD & 16gb RAM. I did a tremendous troubleshooting and finally gave in and reinstalled everything from scratch.


Steps I took to resolve:


  1. Reinstalled a new version of Catalina
  2. Download all programs from scratch, meaning, I did not do a backup and reinstalled from it.
  3. Tested with two monitors, without two monitors, and left the laptop on with the lid open and closed.


And, after 1.5 weeks, the issue is gone. The laptop does not crash at all. I left it on for the whole 1.5 week, and then came back and computer woke like normal.


My theory is, when reinstalling from backup, some power preferences get corrupted. But, I have no way to prove it.


It is tedious to reinstall everything, but it was worth it for me. The bad magic issue may be software issues for some and for others, it may be a hardware one.

Jan 1, 2020 3:22 AM in response to Rempart

Exactly the same config, same year, same problems. Gladly my macOS is still pristine, no drivers / third party program or hardware installed that i could suspect. My notes for the moment, after 3 weeks of random freeze before hard reboots :

  • Sleep mode with usb-c or hdmi screens seems to trigger the crash
  • When the fans starts to go full steam for no reason with no program launched, the freeze + reboot is near
  • Connecting an external hard-drive (usb-c Lacie 2big) seems to consolidate the crashes in sleep mode (i disabled the HD sleep, ofcourse, tested the Drive Alive mode with Amphetamine)
  • I started to monitor programs and temperature activity with iStats, no real pattern visible except the hyper sensitivity to sleep mode and usb-c devices connected (screens and ext. hard-drives) those two things seems to make the kernel unstable after a while. I used Mac computers for the last 15 years and never saw such thing... At that price point it's a shame :(
  • Now to be sure to have no crash during the night, i disconnect all my usb-c devices. In the morning : no crash


I don't think it's only software related, i'll keep an eye open for recalls and maybe schedule an appointment with Apple in the near future.

Jan 3, 2020 1:23 AM in response to Nat_c

Interesting and helpful,


If i'm following all the information gathered in this thead, they are all consistent in the same points that i will list here. In hope someone at Apple will acknowledge this problem as high-level as we can't rely on fairly new and expensive units for everyday use and work :

  • The crashes provoke kernel panics "Bad Magic" (without logs) but not only, some crashes have logged errors
  • Some units reboots after some screen-freeze moments
  • Some reboot happen after the fan kicks at maximum speed, procs. start over-heating with any activity happening
  • They seem to be touching only units with the T2 chip and Catalina OS, to be confirmed
  • For laptops crashes, everyone seems connected to a power-supply
  • A wide range of people here have crashes tied with any device* using usb-c ports or the machine entering-exiting sleep-mode (* hubs / screens / ext. hard-drives)
  • It's not regional
  • Even very recent 16" MBP with fresh iBridge / T2 firmware are plagued with it (J152fAP / J680AP)
  • Seems to be usage and or temperature sensitive as some people use the unit for weeks without problem and then it crashes many times a day without any recovery possible after it begins
  • SMC and PRAM reset seems to be a fairly short fix for a few and not at all for most
  • Very recent replacements units have the same problem
  • Motherboard replacement don't fix the crashes


If you experience an exception to this list please share it, we can maybe narrow down the culprit(s) and hopefully find a temporary fix till Apple takes action.

Jan 12, 2020 9:51 AM in response to Netcracker

This question has already been answered in the thread, this bug has no regional limit.


What defines this kernel panic :

  • Recent hardware with T2 chip on MacOs Catalina (starts late 2018, includes new MBP16 & new MacPros) Some reported the same bug with a different name on HighSierra
  • Common triggers : sleep-wake mode + external devices connected (any device, from hub, to screens and hard drives)
  • Some have short burst of high temperature + maxxed fans + global freeze, right before sudden reboot
  • Non working fixes : Flashing T2 firmware / Changing unit or motherboard
  • Short lived fixes : SMC + PRAM reset / T2 security disabled / HD encrypting disabled
  • More solid fixes : Disable all HD & Screen sleep (energy saver panel) / Screen sleep via shortcut or hot corners works / Disconnect all external devices if you don't disable the energy saver mode while away
  • Note : passes the Apple Service hardware tests but is easy to reproduce once you are plagued with it and know how to trigger it

Jan 16, 2020 10:41 AM in response to Shreyas Ravindra

I am from Netherlands 🇳🇱 So I took the macbook from apple.nl and not any other electronic store. So I had a call with apple support and the guy was not very helpful :(

  1. He said he wanted to re-install the OS again. But from morning I haven't seen it freeze. So I asked him not to repeat it
  2. He said he has *never* heard of this problem BAD MAGIC! (flag set in iBoot panic header) and could be "one off" incident and I was like -- dude seriously, just go look at the apple forums how many people are complaining.


In Netherlands we have a 14 day return policy and I can return and get back 100% of the money if I get the problem again and I hope it doesn't happen. If it does, I will get in touch and update the thread here..


I have a new Macbook Pro - 2019 model - 13 inch screen

My apple id wasn't working either correctly yesterday with this machine.


So my conjecture is this

  1. The apple ID wasn't associated with this macbook in all of apple's database may be
  2. The T2 security chip was probably checking against this and then just gave an error
  3. Today evening my apple ID also started working and then things are okay


Let's wait and watch.. I have some time before I can return it

Jan 19, 2020 12:56 AM in response to orcoonx

I had the problem for the past months (since i started working with connected screens and hard-drives with Catalina) with no real fix except disconnect all external devices before the computer is left to enter sleep mode. That's not what i call acceptable conditions of work for such a "pro" device.


So i took 2 decisions :

  • Wait for the next Catalina update that is being released shortly. If the instability is not totally fixed i'll stick to Apple consumer hotline like glue, till it's replaced or fixed or refunded. Since i can easily reproduce the crash they can't deflect my complains for long.
  • Contact more tech influencers on blogs and youtube to make them aware of what is going on and have a sens of the scale if they already know about it.


The bottom line is that if this crash is widespread and old, the chances it's hardware related are big. And if so, time wise, it's bad news for all Apple users with the T2 chip (all units produced since fall 2017). Finger crossed.


Jan 22, 2020 12:30 AM in response to justin_gordon

Interesting find here, as someone mentioned earlier, disabling the Automatic Graphics Switching (prefs > Energy Saver) seems to have fixed the instability for me. Note that I am using a MBP15 (2019), not sure all T2 units plagued with the BadMagic bug have a primary / secondary graphic cards like MBPs.


That find maybe pinpoints the culprits :

  • Energy management (through the sleep and wake mode)
  • Graphic card switching (might provoke a significant energy change)
  • Third party external devices (screens, ext. hard drives, hubs....people on this thread have no problem with Apple monitors, all other third party devices seem to cause instability)


It all can be narrowed down to the way the units manage energy, T2 / Bridge seems to be somehow involved but that not proven yet. I'm not entirely sure it's only Catalina / HighSierra related because we don't have case of new units (2018+) with older MacOS (Sierra and below), that would not make much sens.


This is a cheap fix. I'm still waiting for the incoming Catalina update to see if it's totally fixed (expectations are low). If not i'll ask for repair / change / refund until it's 100% stable.

Jan 27, 2020 12:08 AM in response to justin_gordon

Personally, I purchased an imac “pro” and a macbook “pro” with the following mindset.


  • These are professional grade units with professional support ( Accused of schizophrenia, because I said there is a thing called as Bad Magic. Last time I checked I did not code Catalina!)
  • They play along well with peripherals (Magically and terribly mistaken. Plug an HDD - Apple’s solution do not plug, plug an external monitor- Apple’s solution: do not plug an external monitor)
  • Reliable and durable ( ha! Bad Magic )
  • I am paying more for the same performance because of all above. ( Is there anything left above?)


We all need to visit mental hospital according to Apple. Because they are doing all this for “customer satisfaction” not that we are experiencing this issue but rather we are spoiled adults who want to call Apple for replacements.

Jan 28, 2020 9:24 PM in response to sea206

My office folks use a Macbook Pro 2019 16" and they connect to external monitors and run quite load of development work on their macbooks. After i requested for a replacement for my macbook, I asked my colleagues if they have ever seen this problem on their macbooks. They have never seen that problem.

They are also running Catalina OS. I have got my replacement device and I already see that IT is way different than the original macbook I had.


  1. After a power ON from shut off my keyboard automatically lights up on login screen
  2. fan runs at high speed only during finalizing an installation and not while running youtube or netflix
  3. I am going to run Netflix on it for some more time today to see if the issue occurs.
  4. I also did a clean installation this time. Didn't restore from my old mac like last time :)


In my opinion, you should just ask for a replacement

Jan 29, 2020 2:02 AM in response to Shreyas Ravindra

That's a good question and the answer is tied to the real world configuration of your office people computers, that thing, none of us here can check.


I worked with my unit (MBP15 2019) for 4 month everyday without any problem, how ? The devil is in the small details, i only used it traveling with just a mouse and a small external hard drive. After that time i used it as my main computer with 2 usb-c screens and a Lacie DAS, and then, only then all **** broke loose. If you read my past posts in this thread you know the rest of the story...


So if you want to answer your own question and have time, here is a quick check list of tests you can do :


  • Randomly select a couple of computers that have a T2 chip. It means they where built and sold after 2018.
  • Check those computers have MacOS Catalina (any version is ok)
  • Be sure to have at least 1 or 2 screens connected to it and another external usb-c device (hub or harddrive, something that draw power from the unit)
  • Let it have a normal day of work or at least some CPU action
  • Put it in sleep mode for the night (no power off) - screens must stay connected and will shut off automaticaly
  • Next morning, move a mouse or press a key : here you wake the unit and will propably have the dreaded reboot, let us know.


All parts of this test are mandatory if you want a thorough result. As far as i understand this bug, T2chip+Bridge and software power management are the culprit.

Feb 12, 2020 5:23 AM in response to elja_markkanen

Might have found a solution:

  1. Disable GPU switching (it only doubled the cost of your machine to have this ability, so dw)
  2. Uninstall absolutely everything
  3. Don't have anything plugged in to the ports, they are only for charging.
  4. Lower your resolution to 720p
  5. Mute audio
  6. Disable security
  7. Disable Filevault


If all else fails, leave the mac switched off.


I hope this helps you reach stability as it has with me. I haven't had a single restart since I started using my computer this way.

Jun 16, 2020 9:00 AM in response to pedro-ale

8 months since I posted this and still no answers. This is pretty much all I've learned since then:

  • It seems less likely to happen if you don't shut down or restart your computer. The longer it stays on and off from sleep, the less it happens.


That's it.


With over 900+ people also having this problem, I'm surprised Apple hasn't at least openly admitted that there's a problem.

Dec 11, 2019 8:14 PM in response to pedro-ale

Has anybody experienced this when the Mac was already plugged in to a power source? Mine seemed to happen when it was running on battery.

I've had my Macbook 16" for 2 weeks (i7 16gb ram 512mb ssd). Today I got this error twice: BAD MAGIC! (flag set in iBoot panic header), no macOS panic log available


The first time was at work. The laptop was not plugged into a power source. I then connected it to a docking station at work that was connected to power and ethernet only.


The 2nd time was just a few minutes ago. The Macbook was on, I then plugged in the power and then pugged it my dongle to USB which is connected to a Logitech Unifying USB receiver and an external IPS 1080p monitor and then I shut the lid and left the room. I came back and it was rebooted and I saw this message when I logged in.


This is the first day I've seen this issue. The only thing I've done differently was the night before - I installed Adobe Acrobat Reader DC and Dropbox.



"BAD MAGIC! (flag set in iBoot panic header)" — Catalina freezing all the time!

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