The “Failed to expand object” error in Veeam Backup & Replication typically occurs when Veeam attempts to enumerate or query a virtual infrastructure object (such as a VM, datastore, cluster, or host) but cannot retrieve its components. This issue is most often related to environment configuration or permission mismatches between Veeam and the underlying vCenter/ESXi infrastructure.
Common Causes and Resolutions
Cause 1: vCenter or ESXi Connectivity Issues
When Veeam cannot communicate properly with vCenter or a managed host, it may fail to expand objects during job initialization or inventory enumeration.
Resolution:
- Verify network connectivity between the Veeam Backup Server and the vCenter/ESXi host.
- In Veeam, go to Backup Infrastructure > Managed Servers, right-click the affected server, and choose Rescan to confirm access.
- If the connection fails, check for DNS resolution issues, SSL certificate mismatches, or firewall restrictions.
Cause 2: Incorrect or Expired Credentials
If the credentials used to connect to vCenter, ESXi, or a Windows repository have changed or expired, Veeam will be unable to access the associated objects.
Resolution:
- Open the General settings > Credentials & Passwords > Datacenter Credential and update any expired passwords and reapply the correct credentials.
- Rerun the job or perform a rescan to confirm successful authentication.
Cause 3: Insufficient Privileges
The account used to connect to the host or vCenter must have adequate privileges to query inventory objects and perform backup operations.
Resolution:
- Ensure the account has at least Read-Only permissions at the vCenter root level, plus additional privileges required for backup and restore tasks.
- If using a service account, confirm it has the same permissions as the original administrative account used for configuration.
- Reconnect the host within Veeam using these credentials and re-run the job.
Additional Notes
- This error often appears in the job log under Task Details with messages similar to:
“Failed to expand object <object_name>.” - If the environment has recently undergone changes (host rename, cluster reconfiguration, or datastore removal), ensure Veeam’s inventory reflects the updated topology.
- After corrections, always Rescan the infrastructure in Veeam and restart the Backup Service if necessary.
If you continue to experience this error or need further assistance, contact Support@Managecast.com for additional troubleshooting guidance.