execution of user datastore procedure has failed

Try the following links for this error:

http://docs.oracle.com/cd/E16655_01/server.121/e26079/drgus.htm

https://community.oracle.com/message/645349

https://community.oracle.com/message/1483510

https://community.oracle.com/message/129790

https://community.oracle.com/message/10409840

https://community.oracle.com/message/10060257

https://community.oracle.com/message/1917993

https://community.oracle.com/message/9200848

https://community.oracle.com/message/80747

https://community.oracle.com/message/14153

https://community.oracle.com/message/14150

https://community.oracle.com/message/2825456

https://community.oracle.com/message/1676835

https://community.oracle.com/message/4088255

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