Issue:
Caldera not opening at all and one suspects issue is related to Xquartz (see advanced section at the bottom of this article).
Xquartz will be active but Caldera will not launch at all
Display errors when starting Caldera from Terminal (/opt/caldera/bin/caldera)
Problem:
Caldera requires a clean Xquartz 2.7.9 install to properly function.
Xquartz 2.8.x has been installed or appeared to have been installed.
Another symptom of a customer having installed 2.8.x but then reinstalled 2.7.9. is that Xquartz automatically re-opens after you close it.
Either way, assume Xquartz 2.8.x was installed, so uninstall both 2.8.x and 2.7.9 before (re)installing Xquartz 2.7.9.
Solution:
Using MacOS Terminal (available under Utilities) copy and paste the following commands (one line at a time)
Uninstall (XQuartz 2.8.x or later)
To uninstall XQuartz 2.8.x or later, execute the following in Terminal (one line at a time):
sudo launchctl unload /Library/LaunchAgents/org.xquartz.startx.plist
sudo launchctl unload /Library/LaunchDaemons/org.xquartz.privileged_startx.plist
sudo rm -rf /opt/X11* /Library/Launch*/org.xquartz.* /Applications/Utilities/XQuartz.app /etc/*paths.d/*XQuartz /usr/X11* /System/Library/Launch*/org.x.* /Applications/Utilities/X11.app /etc/*paths.d/X11
sudo pkgutil --forget org.xquartz.pkg
Uninstall (XQuartz 2.7.x or earlier)
To uninstall XQuartz 2.7.x or earlier, execute the following in Terminal (one line at a time):
sudo launchctl unload /Library/LaunchAgents/org.macosforge.xquartz.startx.plist
sudo launchctl unload /Library/LaunchDaemons/org.macosforge.xquartz.privileged_startx.plist
sudo rm -rf /opt/X11* /Library/Launch*/org.macosforge.xquartz.* /Applications/Utilities/XQuartz.app /etc/*paths.d/*XQuartz /usr/X11* /System/Library/Launch*/org.x.* /Applications/Utilities/X11.app /etc/*paths.d/X11
sudo pkgutil --forget org.macosforge.xquartz.pkg
Caldera V14.1 or older
Once uninstalled, reinstall Xquartz 2.7.9 (<< click the link to download)
Caldera V15.0 or newer
Once uninstalled, reinstall Xquartz 2.8.1 (<< click the link to download)
After the Xquartz reinstall, reboot the computer.
Source: https://www.xquartz.org/FAQs.html
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Advanced:
Error screenshots, just for troubleshooting reference and problem identification.
It appears when both Xquartz 2.7.9 and 2.8.0 are installed that some files are shared. You can unload 2.7.9 using the 2.8.0 command for example.
Error when starting Caldera (14.1 210224, Big Sur) with Xquartz 2.8.0 installed:
Error (or the lack of) after installing Xquartz 2.7.9 (14.1 210224, Big Sur) over the top of the Xquartz 2.8.0 (no uninstall).
Also when closing Xquartz, it will automatically re-open within a few seconds.
Unloading of Xquartz 2.8.0 and then trying to start 2.7.9 which results in display errors.
Uninstall Xquartz 2.7.9
Error after only uninstalling Xquartz 2.7.9 and Xquartz 2.8.0 and trying to start Caldera (just as a test). So make sure to install Xquartz 2.7.9