Error21 - Unable to determine conversion rate to replicate journal

Issue:

Error when trying to post the journal 

"Error21 - Unable to determine conversion rate to replicate journal"

Solution:

The Daily Rates must be defined for both Ledgers.
Each Ledger may have a different rate type assigned (for example Spot in one Ledger and Corporate in the other), so the conversion rates for both rate types must be defined
and must exist on the effective date of the journal, even when using the same currency.

(or)

1. Run the sql scripts below and check the currency code in outputs
a.
select * from gl_ledgers where ledger_id in ( &primary ledger id, &secondary ledger id );
b.
select * from gl_ledger_relationships where source_ledger_id in ( &primary ledger id, &secondary ledger id );
c.
 
select l1.ledger_id, l1.name , l1.currency_code, l2.ledger_id, l2.name,
l2.currency_code, rel.alc_inherit_conversion_type
from gl_ledger_relationships rel, gl_ledgers l1 , gl_ledgers l2
where l1.ledger_id = rel.source_ledger_id
and l1.ledger_category_code = 'PRIMARY'
and l2.ledger_id = rel.target_ledger_id
and l2.ledger_category_code = 'SECONDARY'
and l1.currency_code = l2.currency_code; 
In this case the currency_code in sql1 and sql2 is different, there is a corruption.

If corruption is identified in the sql outputs,development recommends to create a new secondary ledger and use it for transactions. The corrupt ledger should not more be used.
 
Also please note this applies only to Secondary ledgers which have identical currencies. So, it will not work for Reporting ledgers.
There are also cases when the Secondary ledger is configured with a different currency from primary , hence this solution will not apply for such cases either.