How to run Purge Concurrent Request and/or Manager data based on Count

There is a Check Event Alert that runs multiple times for every PO/Requisition Approval in our system resulting in a large number of output and log files (over 150,000) on a weekly basis. We run the Purge Concurrent Request and/or Manager Data request on a daily basis to purge everything older than 7 days (Parameters = ALL, Age, 7). We would like to purge the Check Event Alert based on count as there are so many. We try to use the parameters "ALL, Count, 100000, Alert, Check Event Alert" but the request ends in error:

APP-FND-01564: ORACLE error 1 in request

Cause: request failed due to ORA-00001: unique constraint (%s.%s) violated