Third party sale order qty issue

Hi,

While creating third party sales order: PR has been created for 20 items automaticallyu2026u2026

Now I have created PO w.r.t. PR for 8 qtyu2026.

I did GR for 4 qty and done invoice for the sameu2026

Now when I am trying to create PO again wrt PR for remaining item i.e. qty 12 ( I tried for qty 1 also)..

I am getting error :

Materials for PReq 104, item 00010, already partially ordered

Message no. 06249

Uts