Cant Migrate Two Mailboxes - too many transient failures

[AshJor]

I am currently running in a hybrid environment with 2016 exchange on-premises.

I am around a third of the way through my migration of Mailboxes into the O365 and have succesfully migrated around 700 Mailboxes.

The problem i have is with now 2 Mailboxes that i cant migrate.

they both have the same error "The job encountered too many transient failures (61) and is quitting. The most common failure is CommunicationErrorTransientException/CommunicationException/SocketException with the hit count 46"

theses mailboxes were from different batches and i have also tried to move them via the GUI and also PowerShell as individual moves, unfortunately that fails as well.

I have tried setting the Bad item limit to 100 , this did not help.

a snippet of the error

equest processing continued, stage IncrementalSync.

4/09/2020 6:56:56 AM [ME2PR01MB5108] Stage: IncrementalSync. Percent complete: 95.

4/09/2020 6:56:56 AM [ME2PR01MB5108] Transient error CommunicationErrorTransientException has occurred. The system will retry (17/60, 17/604).

4/09/2020 6:57:29 AM [ME2PR01MB5108] The Microsoft Exchange Mailbox Replication service 'ME2PR01MB5108.ausprd01.prod.outlook.com' (15.20.3348.16 ServerCaps:07FFFFFF, ProxyCaps:1FFFFFFFFFC7FD6DFDBF5FFFFFCB07EFFF, MailboxCaps:, legacyCaps:07FFFFFF) is examining the request.

4/09/2020 6:57:29 AM [ME2PR01MB5108] Content from the Shard mailbox (Mailbox Guid: 91a0ae49-ad12-4ef8-9452-5e92ec53a3a1, Database: 6e462a43-2910-4af3-95a2-3044c001d19b) will be merged into the target mailbox.

4/09/2020 6:57:29 AM [ME2PR01MB5108] Connected to target mailbox 'newdomain.onmicrosoft.com\b7030874-2fc1-4ed1-9248-18e7c0e374e1 (Primary)', database 'AUSPR01DG035-db016', Mailbox server 'ME2PR01MB5108.ausprd01.prod.outlook.com' Version 15.20 (Build 3348.0).

4/09/2020 6:57:30 AM [ME2PR01MB5108] Connected to source mailbox 'newdomain.onmicrosoft.com\b7030874-2fc1-4ed1-9248-18e7c0e374e1 (Primary)', database 'Students_2022', Mailbox server 'SCHOOL-EXCHANGE.school.local' Version 15.1 (Build 1979.0), proxy server 'SCHOOL-EXCHANGE.school.local' 15.1.1979.3 ServerCaps:, ProxyCaps:, MailboxCaps:, legacyCaps:0FFD6FFFBF5FFFFFCB07FFFF.

4/09/2020 6:57:31 AM [ME2PR01MB5108] Request processing continued, stage IncrementalSync.

4/09/2020 6:57:31 AM [ME2PR01MB5108] Stage: IncrementalSync. Percent complete: 95.

4/09/2020 6:57:31 AM [ME2PR01MB5108] Transient error CommunicationErrorTransientException has occurred. The system will retry (18/60, 18/604).

4/09/2020 6:58:03 AM [ME2PR01MB5108] The Microsoft Exchange Mailbox Replication service 'ME2PR01MB5108.ausprd01.prod.outlook.com' (15.20.3348.16 ServerCaps:07FFFFFF, ProxyCaps:1FFFFFFFFFC7FD6DFDBF5FFFFFCB07EFFF, MailboxCaps:, legacyCaps:07FFFFFF) is examining the request.

4/09/2020 6:58:03 AM [ME2PR01MB5108] Content from the Shard mailbox (Mailbox Guid: 91a0ae49-ad12-4ef8-9452-5e92ec53a3a1, Database: 6e462a43-2910-4af3-95a2-3044c001d19b) will be merged into the target mailbox.

4/09/2020 6:58:03 AM [ME2PR01MB5108] Connected to target mailbox 'newdomain.onmicrosoft.com\b7030874-2fc1-4ed1-9248-18e7c0e374e1 (Primary)', database 'AUSPR01DG035-db016', Mailbox server 'ME2PR01MB5108.ausprd01.prod.outlook.com' Version 15.20 (Build 3348.0).

4/09/2020 6:58:04 AM [ME2PR01MB5108] Connected to source mailbox 'newdomain.onmicrosoft.com\b7030874-2fc1-4ed1-9248-18e7c0e374e1 (Primary)', database 'Students_2022', Mailbox server 'SCHOOL-EXCHANGE.school.local' Version 15.1 (Build 1979.0), proxy server 'SCHOOL-EXCHANGE.school.local' 15.1.1979.3 ServerCaps:, ProxyCaps:, MailboxCaps:, legacyCaps:0FFD6FFFBF5FFFFFCB07FFFF.

4/09/2020 6:58:04 AM [ME2PR01MB5108] Request processing continued, stage IncrementalSync.

4/09/2020 6:58:04 AM [ME2PR01MB5108] Stage: IncrementalSync. Percent complete: 95.

4/09/2020 6:58:04 AM [ME2PR01MB5108] Transient error CommunicationErrorTransientException has occurred. The system will retry (19/60, 19/604).

4/09/2020 6:58:34 AM [ME2PR01MB5108] The Microsoft Exchange Mailbox Replication service 'ME2PR01MB5108.ausprd01.prod.outlook.com' (15.20.3348.16 ServerCaps:07FFFFFF, ProxyCaps:1FFFFFFFFFC7FD6DFDBF5FFFFFCB07EFFF, MailboxCaps:, legacyCaps:07FFFFFF) is examining the request.

4/09/2020 6:58:35 AM [ME2PR01MB5108] Content from the Shard mailbox (Mailbox Guid: 91a0ae49-ad12-4ef8-9452-5e92ec53a3a1, Database: 6e462a43-2910-4af3-95a2-3044c001d19b) will be merged into the target mailbox.

4/09/2020 6:58:35 AM [ME2PR01MB5108] Connected to target mailbox 'newdomain.onmicrosoft.com\b7030874-2fc1-4ed1-9248-18e7c0e374e1 (Primary)', database 'AUSPR01DG035-db016', Mailbox server 'ME2PR01MB5108.ausprd01.prod.outlook.com' Version 15.20 (Build 3348.0).

4/09/2020 6:58:35 AM [ME2PR01MB5108] Connected to source mailbox 'newdomain.onmicrosoft.com\b7030874-2fc1-4ed1-9248-18e7c0e374e1 (Primary)', database 'Students_2022', Mailbox server 'SCHOOL-EXCHANGE.school.local' Version 15.1 (Build 1979.0), proxy server 'SCHOOL-EXCHANGE.school.local' 15.1.1979.3 ServerCaps:, ProxyCaps:, MailboxCaps:, legacyCaps:0FFD6FFFBF5FFFFFCB07FFFF.

4/09/2020 6:58:36 AM [ME2PR01MB5108] Request processing continued, stage IncrementalSync.

4/09/2020 6:58:36 AM [ME2PR01MB5108] Stage: IncrementalSync. Percent complete: 95.

4/09/2020 6:58:36 AM [ME2PR01MB5108] Transient error CommunicationErrorTransientException has occurred. The system will retry (20/60, 20/604).

4/09/2020 6:59:07 AM [ME2PR01MB5108] The Microsoft Exchange Mailbox Replication service 'ME2PR01MB5108.ausprd01.prod.outlook.com' (15.20.3348.16 ServerCaps:07FFFFFF, ProxyCaps:1FFFFFFFFFC7FD6DFDBF5FFFFFCB07EFFF, MailboxCaps:, legacyCaps:07FFFFFF) is examining the request.

4/09/2020 6:59:07 AM [ME2PR01MB5108] Content from the Shard mailbox (Mailbox Guid: 91a0ae49-ad12-4ef8-9452-5e92ec53a3a1, Database: 6e462a43-2910-4af3-95a2-3044c001d19b) will be merged into the target mailbox.

4/09/2020 6:59:07 AM [ME2PR01MB5108] Connected to target mailbox 'newdomain.onmicrosoft.com\b7030874-2fc1-4ed1-9248-18e7c0e374e1 (Primary)', database 'AUSPR01DG035-db016', Mailbox server 'ME2PR01MB5108.ausprd01.prod.outlook.com' Version 15.20 (Build 3348.0).

4/09/2020 6:59:08 AM [ME2PR01MB5108] Connected to source mailbox 'newdomain.onmicrosoft.com\b7030874-2fc1-4ed1-9248-18e7c0e374e1 (Primary)', database 'Students_2022', Mailbox server 'SCHOOL-EXCHANGE.school.local' Version 15.1 (Build 1979.0), proxy server 'SCHOOL-EXCHANGE.school.local' 15.1.1979.3 ServerCaps:, ProxyCaps:, MailboxCaps:, legacyCaps:0FFD6FFFBF5FFFFFCB07FFFF.

[#2]

@AshJor 

Hi, do you have the option to move the mailbox to another on-premises mailbox database first, and then migrate to Exchange Online?  I've seen that work sometimes when this error occurs.

Are you completely Exchange 2016 on-prem or do you have some 2010/2013 there too?  If so, try migrating to the Exchange 2016 server first.  I know by the letter of the law you shouldn't have mailboxes on the hybrid server (if you are using the free hybrid licence key), but this would be a temporary move only. 

[#3]

I've been struggling with almost the exact same issue - all but one mailbox moved successfully but this last one just wont go.

The migration log shows normal progression and then  CommunicationErrorTransientException. Once that occurs something breaks and we get the following message forever

The job has been paused temporarily because the mailbox is locked. The job will attempt to continue again after <date/time>

I did read somewhere else that moving to a different database before migrating to 365 can work. Have not tried it yet. If you do, please let us know how if that works!