Ambiguous Quantity Unit for Material with Cost Est. No. &1

What causes this issue?

The Quantity unit for the Material with Cost Estimate Number <(>&<)>V1
is not unique in Table MLDOC_EXTRACT.

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?

Inform your System Administrator.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.