These are the log entries that need more explanations:
PID18.104.22.168 (uamtscheduledmail - DoScheduledEamil) This is not a valid report type for Amethyst. Schedule: 5
This message indicates that a report was added to the schedule list that does not have a valid Amethyst report type. The report will not be attempted to be generated.
Check the schedule settings for this report and possibly check the database and the logs when this report was added to the database.