Link cannot be changed

What causes this issue?

A connection in the data flow needs to be changed but the link cannot be
changed in this constellation. This is due to one of the following
reasons:
The link target is a persistent MultiProvider or an InfoSet. In this
case, the contained object cannot be removed by deleting the link. The
object can only be removed using the maintenance mode of the
MultiProvider or InfoSet.
The link defines a subobject of a semantically partitioned object or an
InfoObject. In this case, the subobjects can only be deleted in the
maintenance mode of the main object.
The link is a persistent transformation or a persistent data transfer
process. In this case, the target object or source object cannot be
changed. You need to delete the object and create it again.

System Response

The link is not change.

How to fix this error?

Change the corresponding objects in the relevant object maintenance
screen or delete the object and create the object again for the new
source objects or target objects.

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.