We have a migration problem, a single 2010 server with all the roles migrating to 2013 with separate CAS and DB roles. Approx 50% of mailboxes are getting stuck and reporting "Transient error MapiExceptionNetworkError has occurred. The system will retry (1/60)" and "Relinquishing job because the mailbox is locked".
I have tried restarting the services suggested in another thread (Mailbox Migration Service and Search) but it makes no difference.
Any suggestions?
Thanks!
Ben