MFC140U.dll was not found, what it means and how to fix it

MFC140U.dll is the Unicode build of the Microsoft Foundation Class library, part of the Visual C++ 2015-2022 redistributable. Desktop programs built with the MFC framework, common in engineering, CAD, and business tools, need it to start, and "was not found" means that runtime is missing or damaged.

The fix, in order

  1. Install the Visual C++ 2015-2022 Redistributable from Microsoft, both vc_redist.x64.exe and vc_redist.x86.exe. The program that failed might be 32-bit even on a 64-bit PC, and it needs its matching flavour. Restart the PC when done.
  2. Already installed? Repair it instead. Settings → Apps → each "Microsoft Visual C++ 2015-2022 Redistributable" → Modify → Repair.
  3. Reinstall or verify the program itself. A damaged program folder can keep failing next to a healthy runtime, so reinstall the program from its official source.
  4. Run Windows Update, then restart. Servicing updates sometimes replace runtime files, and a pending reboot can leave mismatched versions in place.
Do not download MFC140U.dll by itself. DLL download sites offer single files of random versions, sometimes bundled with installers nobody asked for. The DLL belongs to a matched set installed by Microsoft's package, that package is the fix, and it is free.

If it still happens

Check the antivirus quarantine. A quarantined MFC140U.dll looks exactly like a missing one, so restore it from quarantine if it is listed there, then repair the redistributable. Also look inside the failing program's folder for its own copy of MFC140U.dll. If a private copy is older or damaged it overrides the healthy system one, so rename it (add .bak) and relaunch. If only one program fails while others work, that program is damaged, and a clean reinstall is the remaining move.

Common questions

Will the 2010, 2012, or 2013 redistributable fix it? No. MFC140U.dll belongs to the 2015 generation runtime, now served by the 2015-2022 package. Older packages contain their own numbered MFC files and never contain this one.

Is MFC140U.dll part of Windows? No, it ships with the Visual C++ 2015-2022 redistributable, which many programs install alongside themselves. On a PC where nothing has installed it yet, it legitimately does not exist until the package is run.

Related errors

MSVCP140.dll missing · VCRUNTIME140.dll missing · Visual C++ Runtime Library error

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