Login Window Kernel Panic


macrumors 65816
Original poster
Jun 17, 2009
Lincolnshire, England
Hi all,

I've had this this Apple changed the login window was back in Dev 2? Or 3?

All I do is click my user name on the finder bar and click 'Login Window' - then it shows the Kernel Panic.
Weirdly, it doesn't do it all the time, but probably 80% of the time.

A little annoying! Wondering if it's happening to anybody else?
Note: I've since done a clean install, and it still does it!

Any suggestions maybe?

Thank you :)

(I'd show you the console messages, but I don't know which one it is?)



macrumors newbie
Aug 2, 2011
Login Window Kernel Panic - Fast User Switching

I have the sam issue on both of my machines. This kernel panic occurs randomly when clicking user to login, but seems to happen more often when switching to another user while leaving the current user logged in. It also occurs more often on my Mac Pro... I wonder if it is affected by the lag time for the multiple drives needing to spin up by chance. The following is a portion of the crash logs that all looked basically the same.


Interval Since Last Panic Report: 50417 sec
Panics Since Last Report: 3
Anonymous UUID: 3DEC0C33-8B99-4835-9C1E-016D2E2ED221

Sat Jul 30 18:35:52 2011
panic(cpu 0 caller 0x2ccb0f): Kernel trap at 0x01aa8a1e, type 14=page fault, registers:
CR0: 0x8001003b, CR2: 0x0000000c, CR3: 0x00100000, CR4: 0x00000660
EAX: 0x00000000, EBX: 0x8899d144, ECX: 0x09000000, EDX: 0x0af86ea0
CR2: 0x0000000c, EBP: 0x81a93968, ESI: 0x0ef67200, EDI: 0x0d262d60
EFL: 0x00010282, EIP: 0x01aa8a1e, CS: 0x00000008, DS: 0x00000010
Error code: 0x00000000

Backtrace (CPU 0), Frame : Return Address (4 potential args on stack)
0x81a937a8 : 0x22032e (0x6abf4c 0x81a937c8 0x229ef0 0x0)
0x81a937d8 : 0x2ccb0f (0x6b8488 0x1aa8a1e 0xe 0x6b8431)
0x81a93888 : 0x2e2e34 (0x81a938b0 0x81a93898 0x81a938a8 0x8899d144)
0x81a938a8 : 0x1aa8a1e (0xe 0x48 0x81a90070 0x2f0010)
0x81a93968 : 0x1aa3e4d (0xef67200 0x0 0x0 0x0)
0x81a93a38 : 0x1a9db70 (0xd7bde00 0x9c81 0x0 0x0)
0x81a93ce8 : 0x32aa51 (0x81a93d08 0x0 0x81a93d28 0x6a18a8)
0x81a93d28 : 0x3014c7 (0x17365314 0x81a93e24 0x81a93f38 0xd3903e4)
0x81a93d88 : 0x3001d0 (0x81a93e08 0x7fd4 0x81a93e34 0x100)
0x81a93df8 : 0x2efb1a (0x81a93e08 0xd3903e4 0x150db200 0x7fd4)
0x81a93f78 : 0x5f015a (0xdb776b0 0xd3aa114 0xd390328 0x2c52b6)
0x81a93fc8 : 0x2e3977 (0xd3aa110 0x0 0x10 0xbaca910)
Kernel Extensions in backtrace:

BSD process name corresponding to current thread: Finder
Boot args: arch=i386


Though this may not be directly related, a kernel panic occurred also by simply connecting my two currently logged in macs via firewire 800 to do file sharing.
That crash report had the back trace kernel extension related to firewire drives of course.

I have root user enabled on both machines.


macrumors 65816
Original poster
Jun 17, 2009
Lincolnshire, England
Hmm, I wondered if it was my external firewire drive, so I unplugged it...still the same thing. Then I wondered about internal partitions. So I ejected them, but still the same thing.

I only needed it to lock the computer, but I've now resorted to the security pref lock thing, so I haven't had this issue in awhile.

But I know it's still there.

Hopefully Apple will address this soon. :)

Glad I'm not the only one!!


macrumors newbie
Jun 1, 2010
I experienced a login screen kernel panic as well, followed by a restart into another restart upon logging in, which was somehow due in part to my Magic Trackpad not correctly starting? I'm not really sure what happened. It would be recognized by the computer but I couldn't swipe between desktops, and then when I tried to gesture Launchpad it restarted once again. I shut down without recovering my previous session and that fixed it, but it leaves me wary. I've never had any sort of kernel panic/restart-requiring issues before Lion. I really hope it's just the OS for now and it becomes much more stable in time, as I'd hate to think it's related to my install. I have Time Machine enabled, but even if I reinstalled the OS I feel it would be a waste of time to fresh install the OS just to add a layer of what caused the problems with a Time Machine backup (if it's not just a Lion related problem and is something deeper on my end).


macrumors member
Aug 4, 2010
Santa Barbara, CA
Same Problem Here

I too am having this problem and its driving me nuts. Everything worked fine until the Gold Master of 10.7 - once I installed 10.7, this started happening. FIX IT APPLE!
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