DPM Replica Inconsistent Error With Exchange 2010

Recently I came across DPM backups failing on an Exchange 2010 Mailbox Server.

The error it threw on the DPM machine was:

The replica of Exchange Mailbox Database "DB Name" on "server name" is inconsistent with the protected data source. All protection activities for data source will fail until the replica is synchronized with consistency check. You can recover data from existing recovery points, but new recovery points cannot be created until the replica is consistent.

For SharePoint farm, recovery points will continue getting created with the databases that are consistent. To backup inconsistent databases run a consistency check on the farm. (ID 3106)

DPM failed to access the volume \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy\ on "server name".
This could be due to:
1. Cluster failover during backups
2. Inadequate disk space on the volume
(ID 2040 Details: The device is not ready (0x80070015))

The problem was: The Exchange Management Tools installed on the DPM machine were RTM version, while the version of Exchange 2010 is SP3. This caused a mismatch between the eseutil.exe and ese.dll files from the Exchange server to the DPM server.

Always remember when you update Exchange, you need to:
1. Update all of the Management Tools installed other computers such as workstations and DPM Servers
-or-
2. Copy over the new versions of eseutil.exe and ese.dll to your DPM Servers.

That should hopefully cure any inconsistency errors.