Artifactory may fail to start up after upgrade for multiple reasons. Please have a look at the startup logs to determine the cause of the issue and compare them to the solutions below.
Error: Application could not be initialized: Found invalid license, reverting conversions and stopping startup
Cause: Wrong license file was put in or the license file got corrupted
Resolution: Please try moving the $ARTIFACTORY_HOME/etc/artifactory.lic file to another temporary location and restart Artifactory.
After Artifactory starts, please browse to admin → register pro and insert the license in the UI.