System could not determine an update type for flow type &1

What causes this issue?

The system tried to migrate a valuation. For this it attempted to
determine an update type for the migration for contract type &V2& and
flow type &V1&.

System Response

The transaction was terminated.

How to fix this error?

Enter an update type for the migration or carry out the relevant
migration step for contract type &V2& and flow type &V1&.

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.