Failed to process the query
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Try the following links for this error:
http://docs.oracle.com/cd/E16655_01/server.121/e26079/drgus.htm
https://community.oracle.com/message/490245
https://community.oracle.com/message/10463
https://community.oracle.com/message/3461492
https://community.oracle.com/message/2770146
https://community.oracle.com/message/2247283