#21633 (Bug) “Main – DisplayCal is already running” Cannot launch DisplayCal on Mac 10.15.2

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Component: DisplayCAL 3.8.9.1 | Milestone: 3.8.9.2
Created by Steve

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After installing 3.8.9.1  I was first prompted upon launch to give screen recording permissions which I approved. Then it wanted me to quit and relaunch for them to take effect.  I was about to when DisplayCal requested to install Argyll automatically via download, which I cancelled because I already had it downloaded. So I chose the directory and clicked Okay when it froze and I had to force quit.  Upon attempt to relaunch it gave the error DisplayCal is already running.  I checked the force quit application menu, nothing there. I check the Activity Monitor for any DisplayCal processes, nothing there…  Rebooted the Mac. Same Message on launch…  I uninstalled all Displaycal files, restarted the mac, and reinstalled. Same error.  I simply cannot properly launch displaycal.


Screen Shot 2019-12-10 at 6.48.38 PM (image/png | 2019-12-11 00:48:59)


5 comments on ““Main – DisplayCal is already running” Cannot launch DisplayCal on Mac 10.15.2”

  1. Hi Florian,

    I have a similar program, with a “DisplayCal is already running” message popping up, but without actually running the program. Running on Raspbian 10. I removed both Argyll and Displaycal (sudo apt-get purge –auto-remove displaycal) command. Reinstalled, but to no avail.

    You have a suggestion how solve this?

  2. update on my problem and the program is at least starting up. don’t know about the rest, yet. ;-D

    I updated the  “sudo apt-get update”, “sudo apt-get install argyll-ref” and “sudo apt-get install dispcalgui”. Here I made a mistake, since I first had to remove displaycal. AFter doing so, dispcalgui installed. Now we have the 3.7.x version on the RPI.

    i downloaded the 3.8.9.1 version as a .deb file. this I installed with “sudo gdebi-gtk”. And now v3.8.9.1 is running. next step will be to see if my Spyder X is working.
    Sorry for hijacking the original post. I have been able to circumvent the “Displaycal is already running” warning by installing the program in a different route as expected or advertised.

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