in the pricing analysis this is the explanation i got.
the reasons could be an Condition record overflow or the condition record wpuld have been created after the documnet is created.
But i found the record has been mainatined earlier to the creation of document.
this was for MWST condition type in IS Oil. where the tax rate manatined for this condition record is zero%
Since this is a mandatory condition, the document could not be completed.
Your help in this regard is highly appreciated.