Document & has not yet been released

What causes this issue?

You have attempted to post parked document &V1&. This document must,
however, be released before it can be posted. This has not yet taken
place and you are therefore unable to post the document.

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?

Check the document number. If it is correct, you can display the
document. Look at the document header to see the release approval
path. If you know who is responsible for this release approval path,
get in contact with that person.
If not, ask your system administrator to find out from the Customizing
system of Financial Accounting and Business Workflow Organization
who can release the document.

Error message extract from SAP system. Copyright SAP SE.