Document/transaction is being distributed; changes are not possible

What causes this issue?

The document or business transaction is being distributed at the moment,
and therefore cannot be changed. The document/transaction will be ready
for input once it has been distributed successfully.

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?

Try to change the document/transaction again later.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.