In goldengate version 12, while starting the extract,it may abend with below error. 

2016-04-11 12:31:10  ERROR   OGG-00665  OCI Error describe for query (status = 942-ORA-00942: table or view does not exist), SQL<SELECT MOD(, POWER(2, 64)) as property,   opq.flags   FROM$ t, sys.opqtype$ opq   WHERE t.obj# = 4214597 and t.obj#=opq.obj# (+) >.


It clearly indicated, that ggate user is unable to read the dictionary tables.


Grant select on dictionary table to the ggate user in source database.

SQL> grant select any dictionary to ggate;

grant succeeded.


Now start the extract.

ggsci> start extract EXT1