Error: 2305 - [usage_invalid_blocksize] invalid block size supplied

I have a vRanger installation on 7.5.1 running on Windows 2012 R1 that backs up ~250 VMs.  Seemingly out of the blue a couple weeks ago, we started getting the error "Error: 2305 - [usage_invalid_blocksize] invalid block size supplied".  It was progressively affecting more and more VMs each night so I cut it over to a brand new repository where it then worked for two days straight and then failed again last night, this time on 45 VMs.  Relevant information from the log is below.  The red line highlighted below occurs at the beginning of the backup on all VMs that fail with this error.  I should also add that just because a VM fails one night, doesn't mean it wont back that VM up successfully the next night.  Which VMs fail with this error are seemingly random at this point.

[2017-11-13 18:02:49.251]: Finished initialization of backup information successfully.
[2017-11-13 18:02:49.251]: Initialization was sucessful. Backup type to run: Differential
[2017-11-13 18:03:50.031]: A block size change was detected in the vRanger configuration file. The previous blocksize will be used until the retention policy triggers the next Full backup.
[2017-11-13 18:03:56.661]: Retrieving the VM BIOS configuration completed.
[2017-11-13 18:03:58.643]: Checking mounted disks completed.
[2017-11-13 18:04:02.246]: Creating a snapshot for vRanger completed.
[2017-11-13 18:04:10.608]: Loading virtual machine 'server' information completed.
[2017-11-13 18:04:19.142]: Local machine is a VMware virtual machine.
[2017-11-13 18:04:19.423]: Backup task will attempt to use Machine-based VDDK HotAdd.
[2017-11-13 18:06:11.185]: Filtering out content of pagefile for disk: [VMFS_VOLUME] server/server.vmdk
[2017-11-13 18:06:11.185]: Using filter type(s) active map for disk: vix:1:r:vcenter.domain.local\:443:0:[VMFS_VOLUME] server/server.vmdk
[2017-11-13 18:06:13.822]: Backup failed: Error: 2305 - [usage_invalid_blocksize] invalid block size supplied
[2017-11-13 18:06:13.837]: The failed backup task will be retried.
[2017-11-13 18:07:08.049]: Backup failed: Error: 2305 - [usage_invalid_blocksize] invalid block size supplied
[2017-11-13 18:07:08.065]: The failed backup task will be retried.
[2017-11-13 18:08:10.491]: Backup task using VDDK HotAdd failed: Error: 2305 - [usage_invalid_blocksize] invalid block size supplied
[2017-11-13 18:08:10.491]: Check the manual for compatibility issues when attempting Lan-free operations.
[2017-11-13 18:08:10.491]: Backup task will be attempted using a Machine-based VDDK network connection.
[2017-11-13 18:10:32.307]: Filtering out content of pagefile for disk: [VMFS_VOLUME] server/server.vmdk
[2017-11-13 18:10:32.338]: Using filter type(s) active map for disk: vix:1:r:vcenter.domain.local\:443:0:[VMFS_VOLUME] server/server.vmdk
[2017-11-13 18:10:33.618]: Backup failed: Error: 2305 - [usage_invalid_blocksize] invalid block size supplied
[2017-11-13 18:10:33.633]: The failed backup task will be retried.
[2017-11-13 18:11:36.639]: Backup failed: Error: 2305 - [usage_invalid_blocksize] invalid block size supplied
[2017-11-13 18:11:36.655]: The failed backup task will be retried.
[2017-11-13 18:12:41.764]: Updating notes for server completed.
[2017-11-13 18:12:41.795]: Updating VM notes completed.
[2017-11-13 18:12:42.232]: Setting VM event completed.
[2017-11-13 18:12:44.712]: Removing snapshot for vRanger completed.
[2017-11-13 18:12:44.837]: Error: 2305 - [usage_invalid_blocksize] invalid block size supplied