Yosemite Monitors - Out of Order After Reboot?

  • Dear All,

    Has any of you experienced Mac OS 10.10.x Yosemite losing track of the Monitor setup after rebootng? 
    This question applies only to users using Yosemite and multiple monitor setups. (Note, not a Triple Head -- that's still one monitor even if it's split into three outputs.)
    Please let me know if you have seen this.

  • Tech Staff


    Lets say I am working with 2 external monitors/projectors and also started the computer with them attached, I start with my Isadora patch and later I add an additional monitor/projector, then I keep on going with the Isadora patch. After I make a restart the order of the monitor displays are not the same anymore.

    So the best way to have the system keep the same order is to start the computer with all screens attached.

    Is this what you are asking for?

    Best Michel

  • Yes I have an ongoing fight with scenarios like this. Especially when doing museum/art gallery installs.

    With my limited knowledge I believe its Mac's poor way of remembering display preferences. 
    I have found i can not reliably use two monitors/projectors (hardware projectors) I can only use one as Mac OS X doesn't remember which order they should be in; resolution, etc.  

  • Tech Staff

    for the trojan horse I used a mac mini with Yosemite an 6 LED Pico projectors (two of them showed a mirrored output) so at the end there where 5 individual screens, I have used the HDMI out, a ZOTAC miniDisplayPort to Dual HDMI Adapter went into the Thunderbolt input and two USB to HDMI adapters. I controlled everything with screensharing.

    Re-ordering the display in the system settings does not work and after restart reverts to default settings. So before I start with a project I attache all displays and restart the system and work with those settings, up to know it worked without any problems.

    By the way, Isadora is working fine for 2 weeks now, running 24 hours a day.

    Best Michel

  • Hi All,
    I have also had this issue on both Mavericks and Yosemite and it is an Apple issue, imho, mainly if you have multiple video projectors of matching brands and models.

    I tried to troubleshoot it myself using SwitchResX which allows you to set up custom non-apple screen resolutions, in the hope that it would force the screens to lock to the same outputs. But basically if the Mac restarts, the cable outputs seem to be like shuffling a pack of cards... for example, Stage 1 might end up on a different display output since Apple now chose a different one to call 'Display 2'.

    For me this was a particular issue on a Mac Tower with two graphics cards, one using a Matrox. The Matrox did a better job of holding the configuration, but it was not perfect.

    The show was running for a month without me, and the file was too big, too many scenes to be able to switch the actor stage output numbers, so I had to teach the crew to patiently work on unplugging and replugging the cables until they grabbed correctly. Using the Displays preferences was less effective than unplugging and replugging the cables.

    With projectors of different models, it doesn't seem such an issue and Michel's advice will probably work fine. Just let the Mac pick the machine order herself, in the beginning and then don't reorder the outputs yourself.

    I am amazed really... that Apple hasn't figured this issue out before now. Graphics cards have serial numbers for instance... and so do Projectors. How hard is this to do? I don't know... but somehow it seems very amateur of Apple.

  • I agree Jamie. very frustrating.

  • Dear @primaldivine, @skulpture, @DusX and @Michel, and Everyone

    Ok, the initial indications from the theater in NYC who I am working with to solve this problem are this:
    Michel is a genius. ;-) Because I believe his advice was the key to the solution.
    Well, OK.. they are still going through the process of rebooting ten times to a really see if the projector order stays the same. I will report back  to let you know if this test succeeded or failed for them.
    Here's what we did:
    1) Go to ~/Library/Preferences/ByHost/
    2) Delete the file com.apple.windowserver.XXXXXXXX... (the XXXXXX part is quite long and will be different on every machine.) This file holds the display order you've defined previously in the Displays panel of the System Preferences. (Note that _any previously saved setups will be lost_ because of this.)
    3) Reboot
    4) Now – from this point forward – **never** reorder your monitors in the Displays panel of the System Preferences. Instead, you need to physically reorder your cables so that the right image shows up on the right projector/display
    5) Label everything and write down how they are plugged in to the computer, because the cable order is obviously critical now; you can just reorder it in software.
    I hope that helps someone out with this very annoying problem. (Thanks to @k8tefree her help in sorting this [hopefully] out.)
    Best Wishes,

  • Interesting. thanks @mark.

  • Tech Staff


    yes labeling the cables inputs and projectors is really important to never swap the order.

    Best Michel

  • Dear All,

    @k8tefree reports ten reboots in a row with all the monitors showing up in the right order. Again, @Michel is a genius. ;-)
    Best Wishes,

  • I recently (and regularly) work with 2x Optoma GT750E beamers with my Retina MacBook Pro. I haven't seen this issue before. Sounds frustrating. My machines and cabling are all labeled and the outputs have always been identical every time. Is this why I've never encountered this issue before? Are there any steps to recreate it possibly, I can try them out...

  • Dear @mc_monte,

    I think that the way you can make it happen is to start mucking around with the projector order in the Displays panel in the System Preferences. If you reorder the displays, and if they attached devices are of the same make and model, then Mac OS won't always show them in the same order. So, if you never did that -- i.e., reordered the displays – you probably would not have encountered the issue.
    In my procedure above, steps 1 and 2, where you delete the preferences for the Displays panel ensures that you're starting fresh and not dealing with any lingering re-ordered setups. That's probably the key to fixing the situation.

  • Here is something that may help.

    Just a command line tool. I guess the same functions could be inside izzy- does anyone know if this be run from the javascript actor? @DusX?

  • Dear @DusX,

    I'm not convinced about this. I suspect that the problem occurs when you are using multiple hardware devices (e.g., projectors) that are identical - i.e., same model number, resolution, etc.. I have the feeling that Mac OS can't discern which is which, and thus loses the configuration.

    I am not sure how this code (I looked at it) would solve this problem.

  • Tech Staff


    The post comes from @Fred not from @DusX :-).

    Best Michel

  • @Mark, it will not help in that it would keep the correct order when the models are identical. It could however give a utility in Isadora that would allow you to track and reorder displays in the the system without messing with your patch or stage id's. I tagged @DusX as I thought he would know if we can run this command from the JavaScript actor and then create a user actor to reorder outputs.

  • Dear @Fred,

    You shouldn't be able to run a command line thing from Javascript. That would be very dangerous. (Am I wrong @DusX?)
    Well, the code code easily be integrated into Isadora though. For your purposes Fred, what advantage would this have over the normal Displays control panel? I mean, are you saying you'd (for instance) like an actor that could reorganize the displays?
    Best Wishes,

  • I have been encountering the same issue this week. However, although there are multiple output devices of the same make and model, Yosemite is surprisingly remembering the screen order we set up in Display Preferences on reboot.  Clicking on each display in the Display Arrangement window (which reveals a red outline) verifies that the computer is setting the output order the same on reboots.

    However, in Isadora, the Display number relationship to physical output does not remain the same.  "Display 1" in isadora preferences will refer to one output device on one boot, but to another device on another boot, even when these devices do not appear to have been re-ordered by the OS as far as how they appear in Mac Displays Preferences (and the order in which the mouse moves from one projector to the next)
    We don't have the option of reordering the physical plugs, because we have several different types of graphics cards, and are putting the harder work onto the better card and the easier work onto the weaker cards.
    Will try deleting com.apple.windowserver.XXX file, but it sounds like that may leave us with the displays in some strange order that we may have to live with since we can't reorder plugs.  Not the worst thing if it fixes everything else.  But if Yosemite is not actually re-ordering the displays, might we have a different problem?

  • Tech Staff

    @ Fred

    There is no way to gain access to any thing outside of Isadora using Javascript. The environment is very much sandboxed and does not contain any browser specific features like access to the DOM.
    I use TCP-ip to communicate with my external scripts (although I must launch the server first)... in this way I have full system access.

  • I am late to this discussion but I have found that the MAC Pro that I am using will not even boot up with the Barco projector that I am using in conjunction with a Christie projector for another stage. The Mac is a six-core w/16GB and running latest Yosemite. The Christie is getting signal via Long Range DVI Extenders over CAT 6 shielded cable. The Barco is using a VGA run. I can boot with the Christie display plugged but almost always lose my curser into the black background so I just boot with the projectors not connected and then connect them. I know there must be a more sophisticated method but at least this work around has accomplished the goal,

    Related to the MAC issue, when I work at home, I have three external displays connected to my MAC Book Pro, one via mini-display port and two through USB video adapters. The Mac never remembers the arrangement or the display preference.

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