SAP Knowledge Base Article - Public

2420811 - System crashes when you put the Project Task in Supplier Invoice


When you try to put the Project Task in the Supplier Invoice XXX, the system crashes: 

Unexpected error during backend processing

Reproducing the Issue

  1. Go to Supplier Invoicing
  2. Select Invoices and Credit Memos
  3. Seach for the Invoice XXX
  4. Open the Invoice XXX
  5. Select View All
  6. Go to Items
  7. Select the Line Item
  8. Choose Cost Distribution 
  9. Fill the Project Task field
  10. Press Enter
  11. System throws the message: 

 Unexpected error during backend processing


The dump occurs because the Tax Code is missing for Withholding Tax Item. You should maintain the Withholding Tax Classifications for the Country of the Supplier.


  1. Go to Supplier Base
  2. Select Suppliers
  3. Select the Supplier of the Invoice XXX
  4. Open the Supplier
  5. Select View All
  6. Go to Financial Data tab
  7. Select Tax Data subtab
  8. Under Withholding Tax Classifications, select Add Row
  9. Select the Country of the Supplier, the Tax Type and the Tax Rate Type
  10. Add another row if you want more than one Tax Type
  11. Select Save


KBA , AP-SIP , Supplier Invoice Processing , How To


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