Document Number appearing twice.

Hi Experts,

In one document, particular line item of vendor payment is appearing twice with same document number, document type is KZ when checked in FBL3N. User, Date, Time and amount are identical. When checked Vendor account for the same, there is only one line item with respect to above. This is a special G/L transaction as Advance payment.

I also checked Table GLT0 for the same, there is only one entry.

Can anyone advice me, what could be the error for double entry in FBL3N & how to rectify it ?

Madhu.