1. there is resource with CSV connector 126.96.36.199
2. there is user having account on that CSV resource
3. midPoint is upgraded, so CSV connector is also upgraded (JAR file) and the original Connector object is still in repository, a new Connector object is in repository after midPoint start (after upgrade)
4. edit user with the resource from 1.
5. the account will be unlinked when the projection is expanded, because the connector referenced from the CSV resource cannot be found
Workaround: do not click the users until properly migrated the resources (change connectorRef to point to new Connector object)