Error Code 10055 fault InvalidLogin does not have reason

I'm at my wits end here. This has been going on for months. I have worked with EMC support and VMware support. EMC and VMware support have also worked together. We generally have about 25-75 backup jobs fail every night. On the surface, it's a simple authentication issue. Here are the details.

1. I'm using Avamar 7.2.0-401 performing image backups on VMware 6.0

2. There are no vcenter servers being backed up at the time of the failures.

3. This only happens during peak loads

4. I can re-run each job successfully

5. It will fail at any point during the backup process when it is trying to attach to the first or next disk.

6. I have used an AD account and local account in VMware to connect without any difference.

7. VMware says they don't see the authentication errors that Avamar is reporting

8. This happens throughout the backup window

9. This happens across VMware clusters

10. This is not limited to a single proxy.

11. Proxies only see hosts in the same cluster. There is no cross traffic.

12. This has happened on 2 different virtual centers.

Please tell me someone else has seen this and has an answer.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: VixDiskLibVimGetFaultReason: fault InvalidLogin does not have reason.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Error 3014 (listener error VmodlVimFaultInvalidLogin).

2016-10-05 01:02:06 avvcbimage Warning <16041>: VDDK:VixDiskLibVim: Login failure. Callback error 3014 at 2434.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Failed to find the VM. Error 3014 at 2506.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Logout from server.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Clean up callback data.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Clean up after logging out from server.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Logout callback is done.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Logout from server is done.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Login callback is done.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Clean up callback data.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: VixDiskLibVim_FreeNfcTicket: Free NFC ticket.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLibVim: Get NFC ticket completed.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLib: Error occurred when obtaining NFC ticket for: [VNX5300_R5_06] ARPJVXPSC02/ARPJVXPSC02.vmdk. Error 3014 (Insufficient permissions in the host operating system) (fault InvalidLogin, type VmodlVimFaultInvalidLogin, reason: (none given), translated to 3014) at 4515.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLib: VixDiskLib_OpenEx: Cannot open disk [VNX5300_R5_06] ARPJVXPSC02/ARPJVXPSC02.vmdk. Error 3014 (Insufficient permissions in the host operating system) (fault InvalidLogin, type VmodlVimFaultInvalidLogin, reason: (none given), translated to 3014) at 4669.

2016-10-05 01:02:06 avvcbimage Info <16041>: VDDK:VixDiskLib: VixDiskLib_Open: Cannot open disk [VNX5300_R5_06] ARPJVXPSC02/ARPJVXPSC02.vmdk. Error 3014 (Insufficient permissions in the host operating system) at 4707.

2016-10-05 01:02:06 avvcbimage Error <0000>: [IMG0008] Failed to connect to virtual disk [VNX5300_R5_06] ARPJVXPSC02/ARPJVXPSC02.vmdk (3014) (3014) Insufficient permissions in the host operating system
2016-10-05 01:02:06 avvcbimage Info <19644>: Connecting virtual disk [VNX5300_R5_06] ARPJVXPSC02/ARPJVXPSC02.vmdk
2016-10-05 01:02:06 avvcbimage Error <0000>: [IMG0008] VixDiskLib_Open([VNX5300_R5_06] ARPJVXPSC02/ARPJVXPSC02.vmdk) returned (3014) Insufficient permissions in the host operating system
2016-10-05 01:02:06 avvcbimage Info <9772>: Starting graceful (staged) termination, VixDiskLib_Open attempt to connect to virtual disk failed (wrap-up stage)