Using the Oracle splex user account to run splex_add_trigger on a new installation of Shareplex fails with "ORA-00904 table or view does not exist."
The Oracle splex user account does not have the correct permissions to query system tables such as sys.user$, sys.obj$, etc.
This happens because the system account does not have the right permission to grant the Oracle splex user with the required permissions.
Execute ora_setup and make sure all grant statements execute successfully.
If any grant statements fail, manually run those grant statements in sqlplus.
Try executing splex_add_trigger using the Oracle sys account.