Message SAP /DSD/SL_FSR018 - &1 &2 of material &3 could not be converted (&4)

Diagnosis
The attempt to convert &V1& &V2& for the material &V3& into &V4&produced an error.
The quantity could not be converted.

System Response
The system tries to continue calculating with the base unit of measure.If this is not possible, the relevant data will not be processed.

Procedure
Check the underlying master data. If you cannot eliminate the cause,contact your system administrator.

Procedure for System Administration
Note: The error was reported by the function moduleMATERIAL_UNIT_CONVERSION.