When posting via the interface, for example using VF01 /MR01 /MB01 or from within FI (FB01) or when settling CO objects while generating FI documents, the system displays the error message F5302 Document & & is locked by another user. MESSAGE TYPE X short dump. Additional key words
RWIN NRIV, update program, F5302, lock, MESSAGE TYPE X, short dump Cause and prerequisites
DB2 INFORMIX ADABAS, DOCUMENT_POST, LRWCLF01
Due to the read technique (dirty read), the document number to be assigned had to be locked for all database systems except ORACLE in order to prevent two users from receiving the same document number at the same time. Solution
This is caused by a situation during the number assignment which cannot be reconstructed.
https://service.sap.com/sap/support/notes/178545 (SAP Service marketplace login required)