0XC003000A Fix: RPC Enum Value Out of Range in Active Directory

You're running a Windows Server (usually 2016 or 2019) and you see 0XC003000A popping up in the System event log, often alongside Event ID 1001 or a DCOM error. It's cryptic, and the official messages don't help much. Let's cut through that.

The Direct Fix: Reset DCOM Permissions

What's actually happening here is that DCOM (Distributed COM) is trying to call an interface method — say, from Active Directory or WMI — and the RPC runtime can't map the requested enumeration value to anything the server knows about. The most common trigger is a permissions mismatch on the DCOM machine-wide access controls.

Run these steps on the server throwing the error:

1. Open Component Services (run dcomcnfg).
2. Expand Component Services > Computers > My Computer.
3. Right-click My Computer and select Properties.
4. Go to the COM Security tab.
5. Under Access Permissions, click Edit Default.
6. Add ANONYMOUS LOGON with Remote Access allowed (if not present). Also add Everyone with Remote Access allowed. Apply.
7. Under Launch and Activation Permissions, click Edit Default. Add ANONYMOUS LOGON with Remote Launch and Remote Activation allowed. Apply.
8. Restart the server or run net stop RpcSs && net start RpcSs from an admin prompt.

The reason step 3 works is that many remote DCOM calls (like those from a domain controller for NETLOGON or SAM) arrive under the ANONYMOUS LOGON security context. Without those permissions, the RPC layer can't validate the enumeration — it sees a value that doesn't match any known interface pointer and throws 0XC003000A.

Why This Happens in the First Place

The error string RPC_NT_ENUM_VALUE_OUT_OF_RANGE maps to STATUS_ENUM_VALUE_OUT_OF_RANGE in the kernel. The RPC runtime maintains a table of interface IDs and their method numbers. When a remote call asks for method index 7 on an interface that only has 5 methods, you get this code. It's not a network problem — it's a logic mismatch between what the client expects and what the server's RPC runtime has registered.

On Windows Server 2019, Domain Controllers are particularly prone to this when the Active Directory Web Services (ADWS) or WMI provider for AD gets confused after a schema update. The RPC interface version becomes stale.

Less Common Variations

Stale WMI Repository

If the DCOM fix doesn't stick, check the WMI repository. A corrupted repository can cause WMI providers to register the wrong interface versions.

• Open an admin command prompt.
• Run winmgmt /verifyrepository. If it reports inconsistency, proceed.
• Run net stop winmgmt (this also stops dependent services).
• Rename the repository folder: ren C:\Windows\System32\wbem\Repository Repository.old
• Restart the server. WMI will rebuild the repository from scratch.

This works because a fresh repository forces all providers to re-register their interfaces, clearing any version drift.

Conflicting Third-Party DCOM Applications

If you have backup agents, monitoring tools, or custom COM+ applications installed, they might register their own DCOM interfaces that collide with system ones. The fix here is to identify the offender.

• Open Event Viewer and filter for System logs with source DCOM and event ID 10010 or 10016 near the time of the 0XC003000A error.
• Look for a CLSID or AppID. Search that CLSID in the registry under HKEY_CLASSES_ROOT\CLSID to find the owning application.
• Uninstall or reconfigure that application's DCOM permissions via dcomcnfg to match the system defaults.

One real-world case: a backup agent using an old version of the Volume Shadow Copy Service (VSS) interface kept triggering this on a 2022 server. Uninstalling the agent and installing a newer build resolved it permanently.

Prevention

The error doesn't come out of nowhere. It follows patterns. Here's how to avoid it:

• Keep DCOM permissions consistent across all domain controllers. Use Group Policy to enforce COM Security settings if you have multiple DCs — the difference between them is what triggers the mismatch.
• Test schema updates in a lab. Updating the Active Directory schema changes interface GUIDs under the hood. Apply the update to a replica first, let replication settle, then update the rest.
• Monitor the WMI repository health. Run winmgmt /verifyrepository monthly as part of your maintenance script. If it starts failing, you'll catch it before it causes DCOM errors.
• Stick with supported versions of third-party software. That backup agent from 2018 that still works on Server 2016 might not register the same COM interfaces on Server 2022. Check vendor documentation for supported OS versions.

If you followed the fix section and the error is gone, good. If not, the variation section will likely cover your case. The key insight here is that 0XC003000A is almost never a hardware or network issue — it's a mismatch between what a client asks for and what the server's RPC runtime can deliver.