SAP Message 40592 - Automatic value assignment not possible for characteristic & &

Diagnosis
You tried to automatically assign values to a characteristic. For thischaracteristic automatic value assignment is only possible inconjunction with a second characteristic.

Example:
You can only assign values automatically to both PPPI_MATERIAL_QUANTITYand PPPI_UNIT_OF_MEASURE.

Procedure
Assign values simultaneously to dependent characteristics.