Value &1 for characteristic &2 cannot be stored as numerator/denominator

What causes this issue?

You are maintaining a <DS:DE.ATWRT_WS>planned value</> or an actual
value for a characteristic for which you have defined
<DS:DE.LRMEI_WS>proportion or product units</> in the material master.
This value must be stored as a <DS:TX.MENGENUMRECHNUNG>numerator and
denominator for converting</> to the <DS:DE.MEINS>base unit of measure
</>. Numerators and denominators have a maximum length of five
characters.
The value you entered, &V1&, cannot be represented using numerators and
denominators.

System Response

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

How to fix this error?

Change the planned or actual value to a valid value.

Error message extract from SAP system. Copyright SAP SE.