OS X Yosemite Keeps Crashing To Log-In Screen

I have a user with this issue also. It seems to happen more when using an external monitor. I hope Apple can fix it with an update soon.

I found that disconnecting the cable to the external monitor did not cure the problem, though it seemed to delay it.
( I still get "logged out" unexpectedly :-( )

After upgrade to 10.10.2 the crash to login screen related to disconnecting external monitor did not occur any more. However, I had crash to login screen related to sleep/wakeup. So it may solve the problem for some people, but definitely does not solve the problem for all of you. I guess Microsoft was more honest with their BSoD than silent crashing to login screen and restart of all applications now exhibited by Apple.

I Switched my Mac on today for the first time in weeks and still it crashes to login screen and still no update.

i have uninstalled everything to set it back to the day I bought it(August 2014) and have no second monitor but yet it stillif crashes and the only way for it to work is to boot in safe mode.

THis is now a complete joke and I wish I never changed from windows to this..

Same problem as most people on this thread:

-MBP 17", 8 GB, SSD, OSX 10.10.1

-only one user running

-only the laptop display, no external monitor

-session exits to login screen 1++ times a day when swapping applications or connecting external devices (USB, thunderbolt)

-never a crash while I am working within an application

What I can contribute to the thread is that, despite not using an external monitor, I also think the crashes have to do with displays or at least graphics. The reason is that I use a modified color temperature display profile and the crashes are often preceeded by a visible change of color temperature in the display (that looks like the blue default).

RRight switched on this morning as I really needed to print something but couldn't get the Mac to start in safe mode so went with the log in process expecting it to crash back to log in screen but it hasn't.....yet.

last time I switched on it updated "Pages,Numbers and Keynote " now wether these updates have anything to do with the crashes back to log in screen I do not know but it seems to be working so far but my Mac seems to be running a bit slower and I get the odd flicke on the screen.

I Really hope this is fixed and hope this post may help others...

IIt would seem i still have the problem because when in safe mode it no longer says safe mode at the top right of screen...

Jose Navarro wrote:

...... I also think the crashes have to do with displays or at least graphics. The reason is that I use a modified color temperature display profile and the crashes are often preceeded by a visible change of color temperature in the display (that looks like the blue default).

Yes! Me too, is this the elusive thing that these crashes have in common, since not much else seems in common? I am experiencing this same color change / screen flicker type of thing when these (numerous) crashes happen.

I am having this problem too, with the main difference from most people on this thread is that this problem for me started happening after I installed 10.9.5 on 10/29/14. I thought it was just me with the particular apps I had running, until it got more and more frequent and more annoying, and I started doing some troubleshooting of my own. I upgraded to 10.10.1 and the problem did not go away, plus then I got graphic card errors almost on every program I executed. I was trying to capture the exact error with a frame grab, but my system kept crashing. I quickly back-revved to 10.9.5 and I still have the same problem every day, but at least now I don't have the graphic card errors so I can work. I am thinking about back revving to 10.9.4 or waiting to see if a 10.10.2 or later will fix the problem, based on what I read on this thread. Thanks to everyone for posting so I know I'm not alone. This is shocking behavior from an Apple system.

I'm on an 27-inch Late 2012 iMac with no other monitors, accounts, or high-intensity software.

Processor 3.4 GHz Intel Core i7

Memory 8 GB 1600 MHz DDR3

Graphics NVIDIA GeForce GTX 680MX 2048 MB

Software OS X 10.9.5 (13F34)

I have a Macbook Pro at work with an external monitor that I upgraded to Yosemite, and this problem never happens on my laptop.

the idea that the crashes have something to do with graphic is in interesting idea...

the iMac which is having this problem does in fact have a custom color profile set, I had forgotten this. (however no external monitor attached)

So just now I opened up System Preferences -> Displays -> Color and checked the display profile setting.

I set it back to the default "iMac", then a couple seconds later I clicked on another profile setting, and... POOF! the iMac immediately crashed out to the login screen, logging out all users.

after logging back in, I tried to reproduce this behaviour but changing color profiles back and forth several times this time had no effect. So perhaps graphics may have something to do with the problem but I suspect there are other causes...

for example I have had all users spontaneously logged out while the iMac is sitting doing nothing, just the login window visible (e.g. leaving the computer unattended at night, to find all users logged out later in the day or the next morning). at the time, my userid typically might have a static Safari window open, maybe iTunes, but certainly no graphics-intensive app running.

I guess I will leave it set to the default profile now and wait to see if the problem still happens...

Well, I am commenting here with my honest hopes that the Apple Yosemite team finally solves this nightmare! I am no longer a member of their developer program. So, does anybody in this long thread of comments know, if Apple actually realized how serious and widespread this problem is and if it is taken care in beta 10.10.2 (fourth release, I guess is the actual one)?

I am on a MacBook Air (13'', middle of 2013), 1,7 GHz Intel Core i7, 8 GB 1600 MHz DDR, Intel HD Graphics 5000 1536 MB, APPLE SSD SM0512F Media 500 GB, sometimes Thunderbolt display connected sometimes not, Yosemite 10.10.1

Just to add to the phenomena described for the crashes: they all end at the log-in screen (no kernel panic ever reported in the Console protocols), happen 2 to 3 times a day; a reproducible observation is, that before crashing the fan runs at top speed for a couple of minutes, though no processor intense program is running, goes back to silence, comes up again (sometimes cycling through this behavior 4 to 5 times), followed by log-off to the log-in screen. Crashes to the log-in screen also happen at times when the screen is in energy save mode (with fan running crazy as described above) or the processor sleeps (no fan activity before crash). I tried all the recommendations found in this thread. Some of them initially seemed to cure the problem, but they just delayed the time to the next crash. Then the frequency mentioned above became true again.

Altogether left with no rational! Informatics is a science, though, isn't it. Any hopes, hints, help for a brighter future?

Burghardt.

My vote is for Graphics related. My guess is WindowServer I have external monitors it and happens more frequently with the external monitors than without. I am on 10.10.1 as well but with a MacBook Air. I'm trying changing the reduce transparency setting under accessibility to see if it has an impact.

Although I have no suggestions, here's my experience for the sake of adding more data to the conversation. Current setup:

iMac 27" desktop (mid-2011)

10.10.1

Two user accounts

Viewsonic external monitor via Thunderbird adapter

For me, the issue began with the installation of 10.10.1. With few exceptions, the crash to the log-in screen only occurs when the external monitor is on and I awaken the machine from sleep and use fast switching. Interestingly, the crash only seems to occur when fast switching from my wife's account to my account (administrator). She has not reported any crashes when she wakens the machine and fast switches from my account.

Turning the external monitor off (not unplugging from the iMac) seems to eliminate the issue.

Don't know if this helps, but I've enjoyed reading the discussion and certainly hope Apple fixes this bug in the near future.

For those who have followed along this thread and suffered through bashing of Apple, I have to apologize to Apple and to those who put up with my rants, frustrations, and failures. I went through a lot of trial and error for almost 2 months of putting up with panics, reboots and restarts on Yosemite. At last, I have succeeded in fixing this problem, permenantly. All along I was deceived that it was NOT a hardware problem, since I did multiple runs of diagnostics, both standard and advanced on my 21.5" iMac.

Around a year ago I added 4 GB of memory (purchased from Microcenter because Apple branded memory was over twice the price). It never failed any tests, yet when I removed it, "voila!" all my problems disappeared. Yosemite has been stable and solid now for 2 days without any reboots or panics. Same software, same everything with just the memory removed. I really should have known, since I experienced this same "foreign" memory problem on a MacBook several years ago. So, now I have learned a valuable lesson. Don't use anything but Apple certified memory. Saving a few dollars cost me hours and hours of work and frustration, not to mention the agony of defeat.

I can't be sure this will be of any help to others experiencing the panics and login screen issues you are having, but don't rule it out, if you have recently added memory to your Macs. I am now a happy camper, and I understand why my MacBook Pro has not had these issues. It doesn't have any added memory.

My Mac is completely standard,one user account,one monitor bought brand new Aug 2014.

The only thing that has changed I went from Mavericks to Yosemite and then bang my Mac is now broke.