Different order supplier & in PO &

What causes this issue?

You are entering a goods invoice with delivery costs and entered
<LS>Selection supplier</> &V3& as the allocation criterion.
In a goods item for purchase order &V2& supplier &V1& has been entered
in the PO; that is why the item is not selected.
INCLUDE MM_IV_MELDUNGEN OBJECT DOKU ID TX

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check your entries and make any necessary corrections.

Error message extract from SAP system. Copyright SAP SE.