Field &1 in versions of the same material are different

What causes this issue?

You want to activate version type &v2&. First the database field &v1&
was changed from version-dependent to cross-version.
This change is not possible if the field &V1&
is cross-version for all versions of the version type &V2& and
has the same value
However, this is not the case for at least one material.

System Response

The system checks all material versions that have a version type for
which the field &v1& is cross-version.
The activation is cancelled.

How to fix this error?

Correct the inconsistency.

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.