NVP vProxy: VM backup fails with "Failed to download VM config file" Status Code 404
Summary: NetWorker VMware Protection (NVP) Virtual Machine (VM) backups for specific datastores fail. The error returned is an HTTP status code 404 (File not found) when attempting to download VM files from VMware. ...
Symptoms
VM backups through specific VM datastores fail with the following message seen in the backup session log:
YYYY-MM-DDTHH:MM:SSZ ERROR: [@(#) Build number: ##] HTTP Get request failed to download config file '[DATASTORE%2525NAME] VM_NAME/VM_NAME.vmx' using URL 'https://VCENTER_FQDN/folder/VM_NAME/VM_NAME.vmx?dcPath=DATACENTER_NAME&dsName=DATASTORE%2525NAME'. HTTP Status code: 404
The VM session logs can be found in the following locations:
- On the NetWorker Server under the
/nsr/logs/policy/PolicyName/WorkflowNamefolder of the NetWorker Protection Policy and Workflow that backed up the VM. - On the NVP vProxy appliance that performed the backup, under:
/opt/emc/vproxy/runtime/logs/recycle/vbackupd/
There is a special character (for example %) in the VMware datastore name:
Cause
There is a % sign (or other unsupported character) in the datastore name which is resulting in unexpected characters being added to the datastore HTTP request. For example the link in the session log might appear as:
https://VCENTER_FQDN/folder/VM_NAME/VM_NAME.vmx?dcPath=DATACENTER_NAME&dsName=DATASTORE%2525NAME
The link presented should also load from a web browser; however, the URL fails to load with status 404 (Not found).

The NetWorker VMware Integration Guide states that using special characters in datastore names can cause problems with the vProxy, such as failed backups and restores. Special characters include the following:
% & * $ # @ ! \ / : * ? " < > | ; ,
See your version-specific NetWorker VMware Integration Guide for additional details. The guide is available through: https://www.dell.com/support/home/product-support/product/networker/docs
Resolution
Additional Information
HTTP 404 is a general HTTP error code for "Not Found." This KB outlines a specific cause for this failure; however, other issues could cause this same error:
- NVP vProxy: VM backups fail with ERROR: HTTP Get request failed to download config file HTTP Status code: 404
- vProxy: Backups fail with resource not found code -404 "Aging out inactive session"
- vProxy: Backups hang and eventually fail with resource not found code -404
- NVP-vProxy: VM backups fail with error: Failed to download config file