EBR error VDDK:[NFC ERROR] NfcFssrvrProcessErrorMsg NFC_DISKLIB_ERROR

From a pool of 15 VMs 2 failed with the following errors. VMs are all on same Hosts and datastores.  Sometimes there are no errors and other times it's different VMs with same error.  Running vSphere/vCenter 5.5U1.  Networker EBR appliance 1.1.0.149.  Networker 8.2.0.1.  Anybody have any ideas?

Extracted 17 lines, suppressed 3588 lines.

See file "/nsr/logs/policy/DEV_POL/1025367-NYQA-2015-2-4-21-10-39" for complete logs.

Extracted Lines:

2015-02-04 21:05:34 avtar FATAL <19822>: Received EOF or error during change block data read

2015-02-04 21:05:34 avtar Error <10519>: Root hash is not valid, the size of the written block(0) does not match(262144)

2015-02-04 21:10:06 avtar FATAL <5155>: Backup aborted due to earlier errors.  No backup created on the server.

2015-02-04 21:10:06 avtar Info <6149>: Error summary: 3 errors: 10519, 19822, 5155

2015-02-04 21:01:38 avvcbimage Warning <0000>: [IMG0014] Problem logging into URL 'https://vcenter:443/sdk' with session cookie.

2015-02-04 21:01:39 avvcbimage Warning <0000>: [IMG0014] Problem logging into URL 'https://vcenter:443/sdk' with session cookie.

2015-02-04 21:01:39 avvcbimage Warning <0000>: [IMG0014] Problem logging into URL 'https://vcenter:443/sdk' with session cookie.

2015-02-04 21:01:43 avvcbimage Warning <0000>: [IMG0014] Problem logging into URL 'https://vcenter:443/sdk' with session cookie.

2015-02-04 21:01:44 avvcbimage Warning <14669>: The datastore 'NYQA' could not be located on the datacenter

2015-02-04 21:05:34 avvcbimage Warning <16041>: VDDK:[NFC ERROR] NfcFssrvrProcessErrorMsg: received diskLib error 393225 from server: NFC_DISKLIB_ERROR

2015-02-04 21:05:34 avvcbimage Error <0000>: [IMG0008] VixDiskLib_Read() at offset 26156800 length 128 returned 1 (21036749815809) NBD_ERR_DISKLIB

2015-02-04 21:05:34 avvcbimage Error <0000>: [IMG0008] VixDiskLib_Read() ([DATASTORE1] NYQA/NYQA.vmdk) at offset 26156800 length 128 sectors returned (1) (21036749815809) NBD_ERR_DISKLIB

2015-02-04 21:05:34 avvcbimage Error <0000>: [IMG1003] Backup of [DATASTORE1] NYQA/NYQA.vmdk failed

2015-02-04 21:10:06 avvcbimage Warning <6690>: CTL workorder "DEV_POL-1423101653661" non-zero exit status 'code 163: externally cancelled'

2015-02-04 21:10:06 avvcbimage Error <0000>: [IMG0011] Avtar exited with 'code 163: externally cancelled'

2015-02-04T21:10:06.718+04:00 avnwcomm Error <0000>: Plugin returned non-zero exit code (10007). Aborting NetWorker connection.

2015-02-04 21:10:17 DEV_POL_9PM-1423101653661 Warning <0000>: [ctl_spawn] Workorder "DEV_POL-1423101653661" non-zero exit status 'code 3: No such process'