If you want to recover messages from Exchange database backup jobs, then verify that the MediaAgent has the required software.
The MediaAgent must have the following software:
The Exchange package (the package can be installed in restore-only mode)
Microsoft Outlook (64-bit) all versions for PST restores.
Microsoft Outlook (64-bit) 2010 and 2013 versions for restoring to a mailbox.
Visual C++ Redistributable for Visual Studio 2012 Update 4 or a more recent version.
For more information, see the Microsoft article "Visual C++ Redistributable for Visual Studio 2012 Update 4", https://www.microsoft.com/en-us/download/details.aspx?id=30679.
If you installed .NET Framework 4.0 on the MediaAgent, then you must apply the updates that are described in the Microsoft support article "Update for the .NET Framework 4: March, 2011", https://support.microsoft.com/en-us/help/2468871/update-for-the-.net-framework-4-march,-2011.
If you installed .NET Framework 4.5, then no updates are required.