Document does not exist in SAP DMS

Hi

I have done all the DMS settings and able to do the following processes

1. Create a document in CV01N and link PO number in object link tab ( The document is visible in ME23N0

2. Able to link the existing document number in ME22N against the PO

The issue is that when i attach a document using "Create Document" button in pop up window in ME21N/ME22N, the system is throwing an error message "Docuemnt XXX does not exist"

Please help me to solve this issue.

Regards

Raja