Wage type & is not valid for personnel number or plant

What causes this issue?

The wage type specified is not valid. Depending on the data you have
entered this can have the following causes:
If you have entered a personnel number the wage type for this personnel
number must be valid.
If you have not entered a personnel number then the wage type for the
plant specified must be valid.

How to fix this error?

Check the data you have entered: wage type, personnel number, plant.

Error message extract from SAP system. Copyright SAP SE.