Hi Tony.
I am not familiar with Crystal Report, but one thing is obvious here. There are structural differences between 11g and 12c. This is the explanation for ORA-00942. Can you please let me know the relevant SQL Statement or object that is missing? So I can give you a much more specific answer.
Just a remark. Please check if 12c is released for Crystak Report. Generally, Oracle 12c is not yet released by SAP.
Regards,
János