Change pointers for message type & active in client &

What causes this issue?

You have tried to delete the message type and the reduced IDoc type.
In client &V1& the generation of change pointers is still active for
this message type.

How to fix this error?

Make sure that the generation of change pointers for this message type
is deactivated in all clients.

Error message extract from SAP system. Copyright SAP SE.