The Last Error Message verb will attempt to return a string description of the most recent error that caused the execution of the Script Error Alert It may also be set by other error conditions causing the script to execute.
The Last Error Message is preserved across restarts of XTension by being saved in the database and remains valid outside of the Script Error Alert script. You can query this or log it at any time to discover the last scripting error that occurred assuming no other error has happened to overwrite the value.
Prior to XTension v 9.4.31 the error message was not saved in the database and would return an empty string after a restart until the first error occurred in that session.