Account assignment check in parallel GL ledgers like leading ledger

What causes this issue?

A posting for a parallel general ledger is created.

System Response

If the message type is "E" (error), the account assignment is checked
when posting to parallel ledgers of the general ledger just as with
posting to the leading ledger. If the message type is W, S, or I, or if
the message is deactivated, the account assignment is not checked as
rigorously when posting to parallel ledgers only. For example, in such
cases you can use an account with a cost element without specifying an
account assignment object, because the postings are not transferred to
Controlling.

How to fix this error?

In the standard system configuration, this message is issued as a
warning message. However, you can change the message type or deactivate
the message in Customizing.

Procedure for System Administrators

To change the message type of message KI351, go to the Implementation
Guide (IMG) under General Controlling,
<DS:SIMG.SIMG_CFMENUORK3OBA5>Change Message Control</>
(work area KI, message number
351).

Error message extract from SAP system. Copyright SAP SE.