As a part of this explanation , I have taken sales order creation into consideration and showed the process of debugging using breakpoint instead
of using watch point that we do in common.
T. Code : VA01
In the above screen shot you can see the error that was triggered and the following screen shots take you through the process of leveraging this error message to find the root cause of this issue.
Enter ‘/h’ in command field to activate Debugging and click enter
If you Execute now using f8 you will reach your error message point where you can find out your error.
Once you reach the point you need to check the values in kunnr,vkorg,vtweg,spart by double clicking on those fields.
It should now be evident that the issue was a missing combination of the sales area and the customer.
Any queries or suggestions to this document are welcome.
Sambasiva Reddy Gurrala
SAP SD Functional Consultant