Parked document does not exist in Funds Management

What causes this issue?

You have posted a parked document in status "complete".
Parked documents are updated in Funds Management. If a parked document
is changed or actually posted, the old document is read in the FM
update tables. However, this document cannot be found.
If you continue with the posting, you may cause inconsistencies in the
database.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

If you have only just changed or posted the parked document, it is
possible that the posting of the document is not complete. You should
therefore check to the message "Document No. ..... posted". If it does
not yet have a note on it to say that the posting is complete, wait a
few minutes and try again later.
If the parked document has simply not yet been updated, it will have to
be reposted. In this case, you should contact the person responsible.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.