How To Fix VPK1321 - The +/- sign must not be changed

VPK1321 - Overview

• Message type: E = Error

• Message class: VPK1 - SPC Processor Messages

• Message number: 321

• Message text: The +/- sign must not be changed

What causes this issue?

In resource-related billing, you have entered an expenditure to be
billed with a sign different from that for the open expenditure.
In the sales pricing for project or when generating a quotation for
service orders, you have entered a transfer expenditure with a sign
different from that for the planned expenditure.

System Response

The expenditure to be billed, or the transfer expenditure, has been
zeroed out.

How to fix this error?

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

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

VPK1321 - Details

• Certainly! Here's a detailed explanation for the SAP error message VPK1321: "The +/- sign must not be changed":
  
  Error Message:
  VPK1321 - The +/- sign must not be changed
  
  
  Cause:
  This error occurs during the processing of packing instructions or packing proposals in SAP, particularly in the Logistics Execution (LE) or Shipping modules. The message indicates that the system has detected an attempt to change the sign (plus or minus) of a quantity or value that is not allowed.
  In SAP packing or delivery processing, certain quantities or indicators have a fixed sign to represent addition or subtraction of quantities (e.g., adding or removing packaging materials, or handling returns). Changing the sign arbitrarily can lead to inconsistencies in inventory or packing data.
  Typical scenarios causing this error:
  
  Attempting to manually change the sign of a quantity in packing instructions or packing proposals.
  Modifying packing data where the system expects the sign to remain consistent with the original document