Data model &1: namespace/prefix for structure generation not valid

What causes this issue?

Prefix/namespace is filled with a non valid entry. You have chosen a
different entry for the prefix/namespace than in Customizing activity
<DS:SIMG.MDG_VC_USMD004_0>Data Model-Specific Structures</>.

System Response

Data model-specific structures are not generated automatically.

How to fix this error?

For automatic data model specific structure generation, use the same
prefix/namespace as in Customizing activity <LS>Data Model-Specific
Structures</>.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.