Hi,
Please go to SE16 and go to RBKP table. Now, check the value for the field RBSTAT for the invoice document in the table and revert back. If its "D", then check whether the invoice is on hold.
Also check the KBA's: 2009994 - RW011 No subsequent document found in accounting
and 1921454 - Invoice Missing PO history and FI follow-on document and the note: 382797 - MIRO: Analysis and repair for missing follow-up documents
Regards,
AKPT