Backup Fails with Event ID: 517

My W2K12R2 Windows Server Backup utility full backups to another W2K12R2 machine via a SMB share \\10.50.190\13\backup fail with these event log entries below and I found KB's referring to SMB 3.x targets so ruled this out with this W2K12R2 target but have no idea why it's still failing. Can someone help please?

When I view failed files on the backup job I see this:

Log Name:      Application
Source:        Microsoft-Windows-Backup
Date:          7/30/2015 4:53:27 PM
Event ID:      517
Task Category: None
Level:         Error
Keywords:      
User:          SYSTEM
Computer:      watvsm02
Description:
The backup operation that started at '‎2015‎-‎07‎-‎30T19:51:08.833364100Z' has failed with following error code '0x807800C5' (There was a failure in preparing the backup image of one of the volumes in the backup set.). Please review the event details for a solution, and then rerun the backup operation once the issue is resolved.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Microsoft-Windows-Backup" Guid="{1DB28F2E-8F80-4027-8C5A-A11F7F10F62D}" />
    <EventID>517</EventID>
    <Version>1</Version>
    <Level>2</Level>
    <Task>0</Task>
    <Opcode>0</Opcode>
    <Keywords>0x8000000000000000</Keywords>
    <TimeCreated SystemTime="2015-07-30T19:53:27.547648800Z" />
    <EventRecordID>1275</EventRecordID>
    <Correlation />
    <Execution ProcessID="3752" ThreadID="5872" />
    <Channel>Application</Channel>
    <Computer>watvsm02</Computer>
    <Security UserID="S-1-5-18" />
  </System>
  <EventData>
    <Data Name="BackupTime">2015-07-30T19:51:08.833364100Z</Data>
    <Data Name="ErrorCode">0x807800c5</Data>
    <Data Name="ErrorMessage">%%2155348165</Data>
  </EventData>
</Event>






Log Name:      Application
Source:        Windows Error Reporting
Date:          7/30/2015 4:53:27 PM
Event ID:      1001
Task Category: None
Level:         Information
Keywords:      Classic
User:          N/A
Computer:      watvsm02
Description:
Fault bucket , type 0
Event Name: Windows Server Backup Error
Response: Not available
Cab Id: 0

Problem signature:
P1: 4
P2: 1
P3: 0x807800c5
P4: 0x80070015
P5: 0x80070015
P6: 0x807800c5
P7: 0x80070015
P8: 0x00000000
P9: 
P10: 

Attached files:
C:\Windows\Logs\WindowsServerBackup\WBEngine.0.etl

These files may be available here:
C:\ProgramData\Microsoft\Windows\WER\ReportQueue\NonCritical_4_60e9755e71eb5db3a99b1a41c98a59c71fd2e1_00000000_cab_105fd99a

Analysis symbol: 
Rechecking for solution: 0
Report Id: a48fcf88-36f4-11e5-80be-90e2ba7bd86c
Report Status: 4
Hashed bucket: 
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Windows Error Reporting" />
    <EventID Qualifiers="0">1001</EventID>
    <Level>4</Level>
    <Task>0</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2015-07-30T19:53:27.000000000Z" />
    <EventRecordID>1274</EventRecordID>
    <Channel>Application</Channel>
    <Computer>watvsm02</Computer>
    <Security />
  </System>
  <EventData>
    <Data>
    </Data>
    <Data>0</Data>
    <Data>Windows Server Backup Error</Data>
    <Data>Not available</Data>
    <Data>0</Data>
    <Data>4</Data>
    <Data>1</Data>
    <Data>0x807800c5</Data>
    <Data>0x80070015</Data>
    <Data>0x80070015</Data>
    <Data>0x807800c5</Data>
    <Data>0x80070015</Data>
    <Data>0x00000000</Data>
    <Data>
    </Data>
    <Data>
    </Data>
    <Data>
C:\Windows\Logs\WindowsServerBackup\WBEngine.0.etl</Data>
    <Data>C:\ProgramData\Microsoft\Windows\WER\ReportQueue\NonCritical_4_60e9755e71eb5db3a99b1a41c98a59c71fd2e1_00000000_cab_105fd99a</Data>
    <Data>
    </Data>
    <Data>0</Data>
    <Data>a48fcf88-36f4-11e5-80be-90e2ba7bd86c</Data>
    <Data>4</Data>
    <Data>
    </Data>
  </EventData>
</Event>