Multiple backups failing with 'Unable to download config file'

I'm getting a lot of these failures. I can only find one other thread and the fix was 'the client upgraded their infratrucutre'.

83065:nsrvadp_save: The following internal error occurred: Unable to download config file: 'SERVERNAME/SERVERNAME.vmx', HTTP response code: 401, URL: 'https://10.180.20.182/folder/SERVERNAME/SERVERNAME.vmx?dcPath=PATH&dsName=VMware_LUN_36'
90233:nsrvadp_save: Cannot download the VM configuration for VM 'SERVERNAME'.

EDIT: this turned out to be a permissions problem with our Networker service account. Something, somewhere got messed up and VMWare tech support was able to assist us