Issue:
After upgrade to Caldera V150 on High Sierra, get spooler exit with error message when start caldera.
Problem:
Xquartz2.8.1 is not installed properly with installer of V150.
Solution:
Reinstall Xquartz2.8.1 manually, see the install path here under, then reboot the computer will solve the issue.
You can find the Xquartz2.8.1 package under DMG file of V150, then go to DISTRIB>TOOLS>DarwinUpdate>SCRIPTS>Preinstall>XQuartz-2.8.1.pkg