Material number (&1) is not the same as the construction type (initial)

What causes this issue?

Synchronous maintenance of material number and construction type are
recommended for the equipment type in Customizing, or to be precise: If
the material number is maintained, then the construction type should
have the same value.

System Response

The construction type of the equipment was not previously maintained.
The system indicates that to maintain synchronicity, you should change
the construction types to &V1&.

How to fix this error?

Check whether the construction type should be changed and, if
necessary, make these changes manually.

Error message extract from SAP system. Copyright SAP SE.