Deleting current standard cost estimates can cause inconsistencies

What causes this issue?

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

If you delete a current standard cost estimate, the fields for the cost
estimate are set to zero in the material master record. If you use the
material ledger, the standard prices in the material ledger master data
are also deleted when you delete the current standard cost estimate.
The material master record for the material thus does no longer
contains a current standard price from a standard cost estimate.
If you delete an active standard cost estimate, you can no longer
determine scrap, work in process and variations for previous periods.
In certain countires, it is a legal requirement to maintain records of
standard pricing. Therefore, you should check whether you are obliged
by law to keep records of your standard cost estimates. Please also
contact the relevant accounting and inventory management departments.

Error message extract from SAP system. Copyright SAP SE.