More than one reason for deviation entered in layout &1

What causes this issue?

Different causes/reasons for deviation/variance have been entered in the
quantity layout. However, only one can be saved in a confirmation.

System Response

When a confirmation is saved, the reason for deviation is adopted from
the first quantity line in which a quantity has been entered. If reasons
for deviation have been defined for subsequent quantity lines, they are
ignored.

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.