ERROR: ORA-02019: connection description for remote database not found

[LKBrwn_DBA]

....
FROM (
SELECT /*+ DRIVING_SITE (T) NO_MERGE FULL(t) FULL(ct) */
....
FROM
tap --remote_table accessed by dblink -> synonym remote database
, calendar_time ct -- table local database/schema
WHERE t.source_system_id = '016'
....

After you check what Pablo recommends and you still have an issue, change the "tap" from synonym to a view:

CREATE OR REPLACE VIEW tap
AS
   SELECT *
     FROM remote_table@dblink;