What does Windows error code 5920 (ERROR_CLUSTER_NULL_DATA) mean?

ERROR_CLUSTER_NULL_DATA

An internal cluster error occurred. Data was not properly initialized.

ERROR_CLUSTER_NULL_DATA is Win32 error 5920 (0x1720) and belongs to Failover clustering cluster internal data initialization.

Troubleshooting steps

• Record operation, object, and node.
• Record cluster log preceding the null state.
• Record concurrent create, delete, and failover activity.
• Record resource DLL and cluster binary versions.

What to verify

Verify whether required cluster data reached an internal operation without being initialized. Check operation, object, and node together with cluster log preceding the null state.

Handling, retry, and recovery

Collect logs and dumps, verify cluster health and updates, and avoid destructive retries until the missing initialization path is understood.

Practical example

A rare race between object deletion and status processing exposes uninitialized data. Correlated cluster logs identify the transition.

References

• Microsoft: System Error Codes (4000–5999) — reference for error 5920.
• Microsoft: Failover clustering documentation — reference for error 5920.
• Microsoft: Get-ClusterLog — reference for error 5920.
• Microsoft: Troubleshoot unexpected cluster failover — reference for error 5920.