EDI: File '&' will not be processed again

What causes this issue?

The file &v1& has already been processed and will not be processed
again. This file is contained in the table for restarting inbound
processing with the flag "Should be deleted". This means that the file
was processed completely in a previous run but that the subsequent
deletion of the file was not successful.

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?

When inbound processing of a file with the same name is restarted, the
file is not processed until the entry is removed from the list of files
which have not been processed completely.
IF &DEVICE&='SCREEN'
<DS:TRAN.WE08>Execute function</>
ENDIF

Error message extract from SAP system. Copyright SAP SE.