What does Windows error code 5011 (ERROR_OBJECT_IN_LIST) mean?

ERROR_OBJECT_IN_LIST

The object is already in the list.

ERROR_OBJECT_IN_LIST is Win32 error 5011 (0x1393) and belongs to Failover clustering cluster list membership.

Troubleshooting steps

• Record object identity and target list.
• Record first insertion event.
• Record concurrent caller and transaction.
• Record list generation or configuration version.

What to verify

Verify whether the object is already present in the target cluster list or collection. Check object identity and target list together with first insertion event.

Handling, retry, and recovery

Treat equivalent membership as success or remove it through the documented transition before re-adding.

Practical example

Two policy paths both add the same dependency entry.

References

• Microsoft: System Error Codes (4000–5999) — reference for error 5011.
• Microsoft: Failover clustering documentation — reference for error 5011.
• Microsoft: Get-ClusterLog — reference for error 5011.
• Microsoft: Troubleshoot unexpected cluster failover — reference for error 5011.