Facing below error messages in SOCO
1) Product Id is not allowed for :2) Product Id is not allowed for Single Purchase Order
What does it mean?
It is possible the product ID what you have selected is related to other logical system (for example same id for multiple logical systems) . The standard search may use a product which is related to other logical system, which is wrong.
The following notes can help : 2153885,2156548.
If not,please let me know exactly the complete scenario (how, and where are you exp. the errors).