DPM 2012 R2 Error 30231 - Exchange 2013 Protection Group

Hi all I seem to have an issue with DPM since I have changed over to new local disk storage. I have looked on the TechNet wiki here and the error we are getting is not listed - 30231.

I have changed local storage before and used DPMSync to reallocate protection groups space and after a consistency check, backups resume. This time all backups are working as usual apart from the Exchange Backup. Agent on the DPM server and Exchange server are both version 4.2.1594.0.

I have tried stopping protection for the group, whilst retaining data to keep online data, and this has not helped. I have seen this as a solution elsewhere, but very little else on this error.

Here is some of the error log, its a large log so I've only taken a few snippets that have errors in.

0EB4    2494    08/23   15:47:34.481    27  FindPrincipalServerBlock.cs(249)        5FD400E4-F8D7-46C3-8506-346275EAE85C    NORMAL  Found Principal server for DatasourceId = 15ac89e2-c5fa-49a6-9469-3b5a8b163113 Server= <SERVERNAME>
0EB4    1818    08/23   15:47:34.675    18  fsutils.cpp(4046)           WARNING Failed: Hr: = [0x80070002] : Encountered Failure: : lVal : HRESULT_FROM_WIN32(dwError)
0EB4    1C20    08/23   15:47:35.802    27  FsmBlock.cs(178)        5FD400E4-F8D7-46C3-8506-346275EAE85C    WARNING Backup.ReplicaPreBackupBlock : RAPreBackup, StatusReason = Error (StatusCode = -2137454109, ErrorCode = VSSDatasourceCaptionMismatch, workitem = 26865e42-efaa-4a43-8841-b44f2da04fd4)
0EB4    1C20    08/23   15:47:35.802    27  FsmBlock.cs(178)        5FD400E4-F8D7-46C3-8506-346275EAE85C    WARNING <Status xmlns="http://schemas.microsoft.com/2003/dls/StatusMessages.xsd" StatusCode="-2137454109" Reason="Error" CommandID="RAPreBackup" CommandInstanceID="b726ee56-e0ac-40a1-b23f-f134f6b747cc" GuidWorkItem="26865e42-efaa-4a43-8841-b44f2da04fd4" TETaskInstanceID="5fd400e4-f8d7-46c3-8506-346275eae85c"><ErrorInfo xmlns="http://schemas.microsoft.com/2003/dls/GenericAgentStatus.xsd" ErrorCode="30231" DetailedCode="-2137454109" DetailedSource="2"><Parameter Name="AgentTargetServer" Value="<SERVERNAME>"/></ErrorInfo><RAStatus><RAPreBackup xmlns="http://schemas.microsoft.com/2003/dls/ArchiveAgent/StatusMessages.xsd"><BackupTime>131479768557280000</BackupTime><RAPreBackupSubTaskStatus>Completed</RAPreBackupSubTaskStatus><DSStatus><ComponentName>29f315c6-0df0-4e08-ae1e-39b32614f3c5</ComponentName><LogicalPath>Microsoft Exchange Server\Microsoft Information Store\<SERVERNAME></LogicalPath><BackupStamp></BackupStamp><Metadata></Metadata></DSStatus></RAPreBackup></RAStatus></Status>
0EB4    1C20    08/23   15:47:35.819    27  FsmBlock.cs(130)        5FD400E4-F8D7-46C3-8506-346275EAE85C    WARNING Backup.ReplicaPreBackupBlock : <-- Exited FSM block with FAILURE (errorCode = VSSDatasourceCaptionMismatch) ErrorInfo = VSSDatasourceCaptionMismatch 
0EB4    16D8    08/23   15:47:38.990    27  BackupMachine.cs(2185)      5FD400E4-F8D7-46C3-8506-346275EAE85C    WARNING BackupMachine : FAILURE - BACKUP, errorCode=VSSDatasourceCaptionMismatch
0EB4    16D8    08/23   15:47:38.991    01  TaskInstance.cs(803)        5FD400E4-F8D7-46C3-8506-346275EAE85C    WARNING &lt;q1:ErrorInfo ErrorCode="30231" DetailedCode="-2137454109" DetailedSource="2" ExceptionDetails="" xmlns:q1="http://schemas.microsoft.com/2003/dls/GenericAgentStatus.xsd"&gt;

If anyone can help uncover this that would be great.

EDIT - Not sure what has changed but now its throwing 30127 errors, these too are not on any documentation I can find.