Dual monitor login issue!

System Preferences -> Displays -> Arrange, where is the white menu bar located?

The login screen should be on the display with the menu bar indicator. Try draging the menu bar in the arrangement display to the other monitor in the arrangement.

If that is not happening, this would be a change from previous Mac OS X releases.

I am using the mirroring option, and I am also having this problems. The login screen shows up on my MacBookPro, but doesn't show up on my 2nd monitor. Once I have logged in to a user, then logged out, the login screen will be on both monitors. But as soon as I restart the computer, its back to square one with only one screen having the login window. I never had any problems with login screens with previous versions of OS X.

I 'm having the same issue with the Log-in screen appearing on the wrong display but only on one system. I have two dual display set-ups both are running 10.10.2 but only one is exhibiting the log-in on the wrong display. Both have the menu bar placed on the correct display in the System Preferences for Displays.

I would encourage you to file a bug or feature enhancement with Apple at either:

BugReporter

<http://bugreporter.apple.com>

Free ADC (Apple Developer Connection) account needed for BugReporter.

Anyone can get a free account at:

https://developer.apple.com/register/index.action

And/Or

Mac OS X Feedback

<http://www.apple.com/feedback/macosx.html>

IPod Touch Feedback

<http://www.apple.com/feedback/ipodtouch.html>

The more people that report a problem, the more likely it will receive a higher priority. Plus each report will have a different perspective that can help the developer identify the root cause.

No change for me with 10.10.1 release with regards to dual displays. All issues as posted previously persist.

Including windows narrowing and moving down. Not to hijack this thread, but anybody seen that behavior?

So far it seems like I'm alone with Applications resized smaller and repositioned after deep sleep with dual displays

Guess we all have to raise the same display bug problems again via OS X feedback to make sure they hear about the issue.

This worked for me! If you have FileVault enabled, try disabling it. FileVault apparently messes with the transparency of the login screen for safety reasons and disables peripherals (such as an external display) until you log in. You can follow this guide (scroll down): Use FileVault to encrypt the startup disk on your Mac - Apple Support

The list is actually a little bit broader 🙂 fortunately enough :

The OS X Yosemite v10.10.1 Update improves the stability, compatibility, and security of your Mac. This update:

• Improves Wi-Fi reliability
• Improves reliability when connecting to a Microsoft Exchange server
• Resolves an issue that may prevent Mail from sending messages through certain email service providers
• Addresses an issue prevents connecting to remote computers using Back to My Mac
• Resolves an issue where sharing services, Notification Center widgets and Actions may not be available
• Addresses an issue that could cause Notification Center settings to not be retained after a restart
• Addresses an issue that might prevent the Mac App Store from displaying certain updates
• Addresses an issue that could prevent some Mac mini computers from waking from sleep
• Resolves an issue that might prevent Time Machine from displaying older backups
• Addresses an issue that might prevent entering text in Japanese

As they did fix the mac mini login bug (whereby you get an unresponsive system at login if you use external speakers or headphones - present since beta 2!) which I'm glad that one is finally resolved after all these months.

I am also having this issue on my Mac mini following the Yosemite installation. I used to have my primary desktop load up on the left, leaving my right desktop free. Now, following the OS update, the login screen loads on the left but then the primary desktop is set to the right and it can't be changed. I've swapped over where the monitors are plugged in but the primary desktop still loads on the right. How can this be the case?

Any assistance on how this can be resolved would be appreciated.

I'm having the same or a similar issue. I use a Mac Book Pro with a second monitor connected via HDMI port. With Mavericks, I was able to boot computer and use the second external monitor to log in as that's where the log in screen appeared. I was able to enter my password using my bluetooth apple keyboard/mouse. Now with upgrade, I am only able to log in on MBP monitor using built in keyboard. The log in screen does not appear on the 2nd monitor!

Can't figure out how to fix this issue.

I am having similar problems.

Mac mini '12 16GB 256SSD

24" display 1920x1200 + menubar + arranged right, HDMI (main screen)

19" display 1440x900 rotated 90deg (portrait) + arranged left, TB to DVI (side screen to review online data, text documents pdf files, ...)

Sometimes randomly the login will appear on either screen.

Equally randomly one or both screen will flicker on/off during startup and then one of the screens may remain black, typically the login one, rather than have the colored background

Most annoyingly every time my system wakes from sleep, every program window on the 24" screen is narrowed to 900px wide (as if to fit the 19" portrait screen) and in my opinion worse, almost every application window is moved about 240px down from the top menu bar, as to align with the horizontal bottom of the 19" portrait screen. ( 240px diff between 1200 & 1440) So several times a day I'm resizing and rearranging my app windows.

Also seemingly random, I can be in the Finder, Safari, pick any app. Through whatever action there will be a popup or confirmation dialog; and even though I"m on the 24" screen ... that extra dialog comes to the side screen! Last one was emptying the trash, bottom right of 24" screen ... confirmation popup centered on the 19" screen ... two feet over to the left!

Can't do a full screen with menu bar?

If I do one app like open office or libre office full screen, then when I switch to Safari or Finder to look up text or a document, poof my full screen office app disappears ... as if I'm not allowed to have two things going at once. I can only bypass it by manually maximizing apps on both screens.

I've also had major problems with apps not properly resizing to a smaller screen. They seem to exist in a virtual large screen. So if you try to push something from the 24" to the 19", it will remain at whatever size I had it on the large screen, without any access to the resize handle.

It really makes me wonder sometimes what Apple is doing to have these functional regressions and/or bugs.

The screen shot from AppleG33k above, does give me a hint try to realign the portrait one vertically higher. Both my screens are physically top aligned, so I have it factual in arrangement, ... but maybe cheating that may help with the vertical repositioning until Apple fixes this.

I have this problem also after upgrading to Yosemite. I have dual monitors and only turn on the right monitor when I turn on my computer. The monitor on the left (graphics) is only turned on when I use Photoshop or Lightroom to process images. I use it other times also when I want to have two things open at the same time. Generally, though I just use the right monitor.

After upgrading to Yosemite, my right monitor was hazy and I couldn't see the login box. I thought there was something wrong with the upgrade. I eventually found out that by turning on my left monitor, the login was visible. I never had this problem with Maverick. And it is kinda of irritating. I did move the menu bar to the right monitor, but this did not change this behavior.

I've also been having this problem since I updated to Yosemite last fall. What I've realized is that the OS often -but not always- creates additional Spaces at random on startup. For everyone in this thread, after you (re)boot your computer and see the login screen on the wrong display, check in Mission Control (after login of course) to see if the OS has created one or more extra Spaces. I'd be curious to know if everyone is also seeing this behaviour on their systems.

I unfortunately don't have a solution to this problem. I haven't reported it to Apple yet because I don't have more reproducible steps for them than "Yosemite creates random Spaces ar startup". But maybe that's all there is to say...

I'm experiencing a similar problem. Yet, a bit graver one. I have two graphic cards (can use one at a time). One of them is apple's original. the other is flashed. With the flashed one I can't log in - both monitors are black as if switched off. The signal is not put through. Only when I unplug one monitor and leave the other plugged in trough a DVI port, the login screen appears - on the right hand-side monitor. I log in and only after that I plug in the other monitor to be able to use them both. A bit of a nuisance...