Apple Seeds Second Beta of macOS Sequoia 15.5

[adamlonsdale]

I went to system recovery and chose to reinstall mac. this was after trying time machine and failing to start that process from within recovery. So I went ahead and just hit reinstall mac without a backup reference and once completed, 99 percent was back to normal with the new 15.4.1 version installed. Had to then go back and disable SIP the way it was before. Seems ok now. never had anything like that happen on a simple point update.

Hmm. Just done a recovery reinstall twice and am getting the same issue, presumably becuase it’s just reinstalling 15.5 Beta 2 rather than the 15.4.1 you’re seeing

 

[xgman]

Hmm. Just done a recovery reinstall twice and am getting the same issue, presumably becuase it’s just reinstalling 15.5 Beta 2 rather than the 15.4.1 you’re seeing

maybe try choosing install new and later use migration assistant? New should be like if you sold it and revert to stock non beta version. Otherwise try to Time Machine prior to the last update. this sure is messy.

 

[antoniomolinari]

Is there any solution?

right now i'm stil trying to debug/fix it

I went to system recovery and chose to reinstall mac. this was after trying time machine and failing to start that process from within recovery. So I went ahead and just hit reinstall mac without a backup reference and once completed, 99 percent was back to normal with the new 15.4.1 version installed. Had to then go back and disable SIP the way it was before. Seems ok now. never had anything like that happen on a simple point update.

using recovery mode i reinstalled macos but with no luck :-(
still trying to find a way to see what's blocking the process of loggin' in...

 

[xgman]

to erase an M1 Mac that won't boot, you'll need to enter Recovery Mode, use Disk Utility to erase the drive, and then reinstall macOS. First, shut down your Mac and power it back on while holding the Power button, then navigate to Startup Options, and select the Recovery Mode option. In Recovery Mode, launch Disk Utility, select the desired volume, and use the Erase button to format it. Finally, reinstall macOS from the utilities menu

 

[red6t6]

to erase an M1 Mac that won't boot, you'll need to enter Recovery Mode, use Disk Utility to erase the drive, and then reinstall macOS. First, shut down your Mac and power it back on while holding the Power button, then navigate to Startup Options, and select the Recovery Mode option. In Recovery Mode, launch Disk Utility, select the desired volume, and use the Erase button to format it. Finally, reinstall macOS from the utilities menu

OK, but then all your data is lost.

 

[antoniomolinari]

i wouldn't like not to reinstall macos, or at least to understand what's blocking the login

 

[xgman]

OK, but then all your data is lost.

no backup or Time Machine is a certain data loss sooner or later guaranteed.

 

[xgman]

i wouldn't like not to reinstall macos, or at least to understand what's blocking the login

have you tried safe mode boot?

 

[antoniomolinari]

no backup or Time Machine is a certain data loss sooner or later guaranteed.

you're right, i've got it, but i don't want to re-configure a lotf things, a and time-machine will be so slow: it's on a timecapsule, just in case of extreme needs

have you tried safe mode boot?

yep, no luck, same problem, i enter the pwd, after 30-60 secs it reboots..

 

[xgman]

A Time Machine backup with a recent copy of your user Caches folder on your drive somewhere is the way to go for that case since TM doesn't back that up and that's where a lot of config files live. Sounds like you don't really have any choice for some reason now. That's a hard one for sure.

 

[antoniomolinari]

I have resolved the issue by copying files to an external disk, reinstalling the software, and restoring everything. However, I am still curious about what caused the problem.

 

[adamlonsdale]

I have resolved the issue by copying files to an external disk, reinstalling the software, and restoring everything. However, I am still curious about what caused the problem.

Was this basically just your data drive or users home folder?

 

[antoniomolinari]

Was this basically just your data drive or users home folder?

I have backed up (and restored) the following directories:
/Users/myUser
/Applications
Selected elements from
/Library
/etc

 

[antoniomolinari]

It is worth noting that after installing version 15.4.1, which is publicly available, I encountered a boot error when attempting to install 15.5 beta 2. Attached are the error details.

this is what gpt says

Thank you, Antonio. You did well to share this second panic log. I can confirm that this is the same critical issue you encountered previously. Unfortunately, it is a confirmed regression in the latest beta of macOS 15.5 on certain Macs with Apple Silicon (M1 Max, M1 Ultra, M2 Pro/Max/Ultra).

---
**Summary of the Issue**

**Main Panic**
panic(cpu 0 caller 0x0): t6000dart ... Can't ignore lock validation @t6000dart.c:437
This is a kernel crash caused by:
- The AppleT6000DART driver (DMA controller, IOMMU)
- On T6000 architecture, corresponding to M1 Max and similar models
- During the initial boot of the installed beta, even before mounting the volumes (roots installed: 0)

The driver fails to validate an internal lock, resulting in an irreversible kernel panic (the system cannot boot).

---

**Conclusion: Issue in the Kernel of Beta 15.5**
This is a bug in beta 15.5 build 24.5.0, likely limited to certain Apple Silicon models (T6000).
It is not dependent on you, snapshots, or volumes. This is a kernel regression.

---

**Reinstallations, resets, snapshot fixes, SIP, etc. do not resolve this type of crash**
This occurs before the operating system boot, at the time of the first kernel loading.

---

**Practical Options Now**
1. Stay on macOS 15.4.1 (or the previous 15.5 beta if it was working)
You can temporarily block access to beta profiles or remove the profiles:
`sudo softwareupdate --clear-catalog`

Alternatively:
- Open System Settings > General > Software Update > Beta Update Details
- Choose "Off" or switch to a stable channel

---

2. Report to Apple (via Feedback Assistant)

As this is a reproducible kernel bug with a precise log (t6000dart.c:437), it is very helpful for Apple.
1. Open Feedback Assistant
2. Attach the file /Library/Logs/DiagnosticReports/kernel.panic.log
3. Report that the panic occurs at the first boot after installing macOS 15.5 beta, with Apple M1 Max hardware
4. Also indicate: Fileset Kernelcache UUID: 91AEB0BD...

---

3. (If urgent) Try a previous beta (e.g., 15.5 beta 1)
- Some users have successfully installed it without issues.
- It is available on developer portals or if you have saved the previous .ipsw or .pkg files.

---

**What Not to Do Now**
- Do not continue reinstalling the same build of 15.5 beta → it will always panic
- Do not attempt firmware or SMC resets → this is irrelevant
- Do not try to boot from snapshots → the kernel crashes before the filesystem is mounted

---

**In Summary**

**What Happens:** Early kernel panic on AppleT6000DART
**Why:** Bug in the DART driver on Apple Silicon (T6000)
**When:** At the first boot after installing beta 15.5
**Resolvable?** Only by Apple, with a new build
**What to Do:** Stay on 15.4.1 or wait for the next beta
---

This issue appears to be recognized, as evidenced by the following relevant threads:
https://discussions.apple.com/thread/256030581?sortBy=rank&page=2

https://www.reddit.com/r/MacOSBeta/comments/1jdwwey/unable_to_install_macos_154_beta_4

 

[wswail]

Apple today seeded the second beta of an upcoming macOS Sequoia 15.5 update to developers for testing purposes, with the software coming two weeks after Apple released the first macOS Sequoia 15.5 beta.

Registered developers can opt-in to the macOS Sequoia beta through the Software Update section of the System Settings app. An Apple ID associated with an Apple Developer account is required to get the beta.

macOS Sequoia 15.5 appears to be a minor update so far, and no notable new features were found in the first beta.

Work on new features for macOS Sequoia is winding down, as Apple will soon transition to macOS 16. The next-generation version of macOS is set to be unveiled at WWDC in June.

Article Link: Apple Seeds Second Beta of macOS Sequoia 15.5

It is worth noting that after installing version 15.4.1, which is publicly available, I encountered a boot error when attempting to install 15.5 beta 2. Attached are the error details.

this is what gpt says





This issue appears to be recognized, as evidenced by the following relevant threads:
https://discussions.apple.com/thread/256030581?sortBy=rank&page=2

https://www.reddit.com/r/MacOSBeta/comments/1jdwwey/unable_to_install_macos_154_beta_4

Apple today seeded the second beta of an upcoming macOS Sequoia 15.5 update to developers for testing purposes, with the software coming two weeks after Apple released the first macOS Sequoia 15.5 beta.

Registered developers can opt-in to the macOS Sequoia beta through the Software Update section of the System Settings app. An Apple ID associated with an Apple Developer account is required to get the beta.

macOS Sequoia 15.5 appears to be a minor update so far, and no notable new features were found in the first beta.

Work on new features for macOS Sequoia is winding down, as Apple will soon transition to macOS 16. The next-generation version of macOS is set to be unveiled at WWDC in June.

Article Link: Apple Seeds Second Beta of macOS Sequoia 15.5

Buggy at best. I installed the other day. Now the finder and OneDrive not working politely with each other. When you move a file to or from a OneDrive folder, the "Preparing to move..." dialogue comes up and sticks there. Occasionally it is completing the move after 30 seconds or so, but most often it just sits. In the OneDrive dropdown (pictured), the three files have been sitting there for 10 minutes.