Generated serial number in document code is wrong. If document code is generated automatically e.g. AZ-EOB-001; AZ-EOB-002; AZ-EOB-003; AZ-EOB-004… and someone creates new document and manually sets serial number e.g. 300 then document is created with this document code 'AZ-EOB-300'. Since then, each document that has been added further continues from this point 300, 301, 302..
1. Use Search Form in ProjectWise Explorer to search all documents that have incorrect document code e.g. 'AZ-EOB-3*'.
2. Export those documents with incorrect document code to local drive (so you could import them later with the correct document code).
3. Delete those documents.