In case of an unknown error on the end user system, the user can enable a log file and sent it to you. You could then send this file to support.
•Press the Options button within the License Viewer
•Select - Error tracking enabled
•Select a path for the logfile
Restart the application until the error appears and then open a support ticket. ZIP all files with the extension .log and attach it to the ticket. The user can then disable the error tracking.