There are still unprocessed queues (&2) with status &1 for the delivery

What causes this issue?

At least one unprocessed entry exists in transaction SMQ2, with queue
name &v2& in status &v1&.

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 status &v1& has the value RUNNING or RETRY, wait a few minutes then
repeat this procedure. The queue entry is usually processed a
utomatically. If several minutes pass without this happening, contact
your system administrator or follow the steps below.

Procedure for System Administrators

Check status &v1& of queue entry &v2& in transaction SMQ2.
If the status is READY, register the queues so that they can be
processed automatically, or start the entry manually.
If the status is RETRY, wait a few minutes to see whether the entry is
processed automatically. If this is not the case, process the entry
manually. In addition, check the settings in transaction SMQR to see
whether the number of retries is high enough (> 0).
If the status is SYSFAIL or of another error status, start the entry
manually to check whether the error was temporary or permanent. If the
error occurs again, analyze the error message. For example, if the error
is due to a missing configuration, perform this configuration.
Note: Never delete an entry from SMQ2 manually.

Error message extract from SAP system. Copyright SAP SE.