Fix RPC_E_SERVER_CANTUNMARSHAL_DATA (0X8001000E) in Minutes

RPC_E_SERVER_CANTUNMARSHAL_DATA (0X8001000E) – What's Happening?

This error pops up when a COM or DCOM call fails on the receiving end. The server got your data but can't decode it—either because memory is tight, the marshaling format is busted, or the interface isn't registered right. I've seen this most often in Windows Server 2016/2019 environments when a remote COM component (like an Excel automation or a custom COM+ app) tries to hand off structured data and chokes.

Quick Fix (30 seconds): Reboot and Retry

Before you dive into registry edits, try the simplest thing: reboot the server where the COM object lives. I know it sounds basic, but memory fragmentation or a stuck COM surrogate can cause this. Restart, then run your operation again. If it clears, you're done. If not, move on.

Moderate Fix (5 minutes): Increase Virtual Memory

Low memory is the #1 trigger for 0x8001000E. The COM subsystem needs contiguous memory for marshaling buffers. When the system's paging file is too small, allocations fail. Here's the fix:

1. Open System Properties (Win + R, type sysdm.cpl, Enter).
2. Go to Advanced tab → Performance → Settings → Advanced tab.
3. Under Virtual memory, click Change.
4. Uncheck Automatically manage paging file size.
5. Select the drive with your OS, then choose Custom size.
6. Set Initial size to 1.5× your RAM and Maximum size to 3× your RAM. For example, 16 GB RAM → initial 24576 MB, max 49152 MB.
7. Click Set, then OK all the way out. Reboot.

This gives the COM subsystem breathing room. I've fixed a ton of "0x8001000E" calls on SQL Server Reporting Services this way.

Advanced Fix (15+ minutes): Repair DCOM Permissions and Interface Registration

If rebooting and more memory didn't work, the problem is likely a misconfigured DCOM object or a corrupt interface proxy/stub. Let's tackle both.

Step 1: Verify the COM Object Exists and Is Accessible

Open Component Services (run dcomcnfg). Navigate to Component Services → Computers → My Computer → DCOM Config. Find the CLSID or App ID of the component throwing the error. Right-click → Properties.

• On the Security tab, ensure Launch and Activation Permissions and Access Permissions include the user account running your client process (e.g., NETWORK SERVICE, or your service account).
• On the Identity tab, try setting it to The interactive user for testing. If it works, you know the account permissions are the culprit.

Step 2: Re-register the Component's DLLs

Often, the error means the server doesn't have the right proxy/stub DLL for the interface. Find the component's DLL(s) on the server, then re-register them:

regsvr32 /u C:\Path\To\YourComponent.dll
regsvr32 C:\Path\To\YourComponent.dll

Do the same for any dependency DLLs (like msxml6.dll or stdole2.tlb). Run this from an admin command prompt.

Step 3: Check for Corrupted COM+ Catalog

If the component is a COM+ application, the catalog might be corrupted. Open an admin command prompt and run:

regsvr32 /s /n /i:MSXML comsvcs.dll
regsvr32 /s /n /i:MSXML comadmin.dll

Then restart the COM+ System Application service (services.msc → find it → right-click → Restart).

Step 4: System File Check

As a last resort, run System File Checker to repair core COM files:

sfc /scannow

Reboot after.

Still Stuck?

If none of these work, the problem might be a third-party COM component with a bug—check for updates from the vendor. Also, enable COM tracing using tracerpt or COM+ Event System logs to see exactly where it fails. But in 90% of cases, the virtual memory or DCOM permission fix does it.

You've got this. Errors like this are frustrating, but they're almost always solvable with a structured approach.