1 Everything works fine if run manually.
2 If it’s runned as schedule, there will be the error message:"System.Data.OracleClient requires Oracle client software version 8.1.7 or greater.
Solution:
1 Install Oracle client on every single one of the web front end server. If there is the sercive on the application server, install it to the application server, too.
2 Restart the SharePoint timer service.
Applies for: SharePoint 2013, SharePoint 2010