Sales price for & & & & could not be found

What causes this issue?

The sales price valuation is active in the valuation area.
The system could not determine a sales price for material &V2&, unit of
entry &V3&, and plant &V4& for the specified posting date.
Pricing conditions may not be defined for the material.

How to fix this error?

Check the definition of the sales price.
<DS:TRAN.VKP1>Proceed</>
If you post this movement without a sales value, the movement will be
posted at the average sales price. This does not have to correspond to
the conditions.

Error message extract from SAP system. Copyright SAP SE.