The Data Retention Policy is set to Purge and the Data Retention Period (days) for Event Table is set to 120 days, but looking at the Archive Expert, the History (Days) is above 120 days.
Enabled the following SRM module in debug mode, and wait until midnight. At that time the SRM will trigger the Archiver.
SRM - Tools - Archiver
Error found in Tomcat log file (stdout.log):
Apr 19, 2018 00:01:31.467 (CrystalOnlyUserManager) (SRMArchiverLog) - (ERROR) - Could not prune source event records
Caused by: org.springframework.dao.CannotAcquireLockException: PreparedStatementCallback; SQL [DELETE FROM event WHERE time < ?]; Lock wait timeout exceeded; try restarting transaction; nested exception is java.sql.SQLException: Lock wait timeout exceeded; try restarting transaction