How to Fix Power Query “Container exited unexpectedly” (Error 0x80040154)

The error "Container exited unexpectedly with code 0x80040154" occurs when Power Query’s isolated evaluation process (Microsoft.Mashup.Container.*.exe) crashes immediately upon launch or during a query refresh. The hexadecimal code 0x80040154 is the standard Windows COM system code for REGDB_E_CLASSNOTREG (“Class not registered”). This indicates that the mashup container attempted to call a required Windows COM component, database driver, or runtime library that is either corrupt, missing, or mismatched with your Office installation’s architecture (32-bit vs. 64-bit).

Fast Fix

Error 0x80040154 means “Class not registered.” Close Excel, press Win + I to open Windows Settings, navigate to Installed Apps, select Microsoft 365, click Modify, and choose Online Repair. This re-registers missing COM objects and Office DLLs. If querying local database files (Access, Excel, or text), install the matching 64-bit or 32-bit Microsoft Access Database Engine Redistributable.

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Diagnostic Snapshot

Property	Details
System Error Code	0x80040154 (REGDB_E_CLASSNOTREG / Class Not Registered)
Failing Process	Microsoft.Mashup.Container.NetFX45.exe or Microsoft.Mashup.Container.Loader.exe
Primary Root Causes	Corrupted COM class registrations, missing Access Database Engine (ACE), 32-bit/64-bit driver mismatches, or antivirus sandboxing
Recovery Path	Office Online Repair $\rightarrow$ Driver installation $\rightarrow$ Mashup cache reset

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Why the Container Crashes

To prevent data refresh failures from crashing the entire Excel application, Power Query isolates query evaluations inside out-of-process workers known as Mashup Containers:

[EXCEL.EXE]
    │
    └── Launches Subprocess ──► [Microsoft.Mashup.Container.exe]
                                          │
                                   Calls Windows COM ──► [ACE OLEDB / .NET Runtime]
                                                                  │
                                                            MISSING / UNREGISTERED:
                                                            "Crash: 0x80040154"

When a container starts up to evaluate a query, it initializes the Windows COM registry to load necessary data providers (such as the Microsoft Access Database Engine ACE.OLEDB for local files, or .NET framework networking components).

If a recent Windows update, incomplete Office patch, or third-party program broke the COM registration keys in the Windows Registry (HKEY_CLASSES_ROOT\CLSID), the container encounters an unhandled execution fault when requesting the class ID. Because the container process cannot establish its required dependencies, it exits unexpectedly and returns code 0x80040154.

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Step-by-Step Resolution

Step 1: Run an Online Repair of Microsoft 365

A standard Quick Repair only scans local files, but an Online Repair completely rewrites and re-registers the COM class identifiers used by Office and Power Query in the Windows Registry.

1. Close all open Office applications (Excel, Word, Outlook, Teams).
2. Right-click the Windows Start button and select Installed apps (or Apps and Features).
3. Scroll down and locate Microsoft 365 Apps for enterprise (or your version of Microsoft Office).
4. Click the three dots (...) next to the installation and select Modify.
5. Select Online Repair and click Repair.
6. Wait for the repair process to complete, then restart your computer.

Windows Settings > Installed Apps > Microsoft 365 > Modify
  ├── ( ) Quick Repair
  └── (o) Online Repair  <-- Resolves missing 0x80040154 COM registrations

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Step 2: Install or Reinstall the Matching Access Database Engine

If the crash occurs specifically when connecting to .xlsx, .csv, .txt, or .accdb files, the issue is almost always a missing or corrupted Microsoft Access Database Engine provider.

1. In Excel, navigate to File > Account > About Excel and check whether your build is 32-bit or 64-bit.
2. Download the official Microsoft Access Database Engine Redistributable directly from Microsoft.
3. Install the architecture that matches your Office build:
   • Office 64-bit $\rightarrow$ install AccessDatabaseEngine_X64.exe
   • Office 32-bit $\rightarrow$ install AccessDatabaseEngine.exe (32-bit)
4. Relaunch Excel and attempt to refresh the query.

For detailed diagnostics on missing database engine providers, see “Data Source.Error: The Microsoft.ACE.OLEDB.12.0 provider is not registered”.

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Step 3: Clear the Corrupted Mashup User Cache

If previous container evaluations crashed, stale cached metadata in your local user profile can cause new container processes to terminate upon reading the corrupt state.

1. Close Excel completely.
2. Press Win + R, paste the following path into the Run dialog, and press Enter: %LocalAppData%\Microsoft\Office\16.0\PowerQuery
3. Delete all files and folders located inside this directory.
4. Next, navigate to: %LocalAppData%\Microsoft\Power Query
5. If this folder exists, delete its contents as well.
6. Open Excel, launch the Power Query Editor, and click Refresh Preview.

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Step 4: Exclude Mashup Containers from Antivirus Deep Inspection

Certain enterprise endpoint detection and response (EDR) agents (such as CrowdStrike Falcon, SentinelOne, or Windows Defender Exploit Guard) flag Microsoft.Mashup.Container.*.exe as a suspicious subprocess when it attempts dynamic memory allocations or COM handshakes.

Diagnostic Test:

• Temporarily disable third-party endpoint protection (if permitted by enterprise policy).
• If the refresh succeeds without throwing 0x80040154, request that your IT administrator add an exclusion for the Power Query container binaries located in:
  C:\Program Files\Microsoft Office\root\Office16\ADDINS\Microsoft Power Query for Excel Integrated\bin\

If your queries consistently encounter memory allocation crashes rather than COM registration faults, see Troubleshooting “Evaluation ran out of memory” in the Power Query Engine. For open file handle collisions that stall worker processes, review How to Fix “The process cannot access the file because it is being used” (PQ). If Excel cannot open reliably even in Safe Mode, consult How to Fix “Excel could not open in Safe Mode” Diagnostic.