ORA-12840

Doc ID 2289797.1

parallel_max_servers=0

alter session disable parallel dml;
alter session disable parallel query;
alter session disable parallel ddl;
Session altered.

Although parallel_max_servers=0, there was an append hint used in an insert statement called from a trigger

SOLUTION

Remove  /*+ APPEND*/ in any insert statements in the package or any trigger that gets executed when the package / procedure gets called.