Error: "Conversion failed when converting datetime from character string", during Reporting Aggre (4335883)

A gathering task fails during the Reporting Aggregation phase with the following error: "The following error occurred while processing a data object for a given gathering: Error in Executing SQL Statement - Message: Conversion failed when converting datetime from character string;; SQL Statement = EXEC PR_CalculateRollups"

The MessageStats SQL database is not set to the correct compatibilty mode for the SQL server hosting the database.

To change the Compatibility Level:

1. Open SQL Management Studio
2. Connect to the server that host the MessageStats Database
3. Right click on the MessageStats Database and select properties.
4. Click on the options tab
5. Change the Compatibility level to match the version of the SQL Server
6. Click OK

Setting the compatibility level to 90 sets the MessageStats database to SQL 2005 compatibility level.