Verifying and Repairing the Visual C++ Runtime Used by Athena 6

Applies to: Athena 6 running on Windows 10 and Windows 11 machines.

Athena 6 depends on the Microsoft Visual C++ runtime, a set of system files that the Athena 6 installer adds to Windows. On some PCs, that runtime is missing from Windows even though Athena 6 appears to run normally. This article explains why that happens, how to check a PC, and how to fix it.

Summary

• Athena 6 needs six runtime files from Microsoft: 
  VCRUNTIME140.dll, VCRUNTIME140_1.dll, MSVCP140.dll, MSVCP140_1.dll, MSVCP140_2.dll and MSVCP140_ATOMIC_WAIT.dll.
• The correct location for these files is the Windows system folder, C:\Windows\System32.
• If they are missing there, Windows may silently use a copy that belongs to another program, most often Microsoft OneDrive. Athena 6 still starts, but it now depends on that other program.
• The fix is to reinstall the Microsoft Visual C++ Redistributable. It takes about one minute.

Why this Happens

Many programs ship their own private copy of the Visual C++ runtime inside their installation folder. Microsoft OneDrive, Mozilla Firefox and Microsoft PowerToys all do this. Normally those private copies are invisible to other programs, because Windows always looks in its own system folder first.

Microsoft OneDrive is different in one respect: its installer adds its program folder to the Windows search path. When the runtime is missing from the system folder, Windows keeps searching and finds OneDrive's copy. Athena 6 then loads its runtime from a folder such as:

C:\Program Files\Microsoft OneDrive\26.153.0809.0004\

This is OneDrive's program folder, not your synced OneDrive documents. It has nothing to do with where Athena 6 is installed or where your files are stored.

Why It Matters

Athena 6 works in this state, so there is no immediate error. The risk is what happens later:

• When OneDrive updates, its version-numbered folder changes. When OneDrive is uninstalled, the folder disappears. Either way Athena 6 can stop starting, with a message like "The code execution cannot proceed because VCRUNTIME140.dll was not found."
• The runtime version in use is whatever OneDrive happens to ship, not the one Athena 6 was tested with.

This condition does not by itself cause Athena 6 to crash while it is running. It is a stability risk for starting the application.

Checking a PC

1. Open a Command Prompt. Press the Windows key, type cmd, and press Enter.

2. Type the following command and press Enter:

   where.exe vcruntime140.dll

3. Read the first line of the result.

Healthy PC. The first line is the Windows system folder:

C:\Windows\System32\vcruntime140.dll

Additional lines after it are fine. They are the private copies belonging to other programs.

PC that needs repair. The first line points somewhere else, for example a Microsoft OneDrive folder, or the command reports that it could not find the file:

C:\Program Files\Microsoft OneDrive\26.153.0809.0004\vcruntime140.dll

INFO: Could not find files for the given pattern(s).

In either case, continue with the repair below.

Repairing the Runtime

1. Close Athena 6.
2. Download the official 64-bit Visual C++ Redistributable from Microsoft: https://aka.ms/vs/17/release/vc_redist.x64.exe
3. Run the downloaded file. If it offers Repair, choose Repair. Otherwise accept the license and choose Install.
4. Restart the PC if the installer asks you to.
5. Run the check above again. The first line should now be C:\Windows\System32\vcruntime140.dll.
6. Start Athena 6.

Alternatively, run the Athena 6 installer again. It installs the same Microsoft package as part of the setup.

Do not download individual .dll files from third-party websites or copy them from another program's folder into C:\Windows\System32. Only the Microsoft installer places the correct, signed versions.

Symptoms this Resolves

• Athena 6 will not start and reports that VCRUNTIME140.dll, VCRUNTIME140_1.dll or MSVCP140.dll was not found.
• Athena 6 stopped starting after Microsoft OneDrive was updated, moved or uninstalled.
• Support has told you that Athena 6 on your PC is loading its runtime from a OneDrive folder.