What You Will See
On a freshly installed Windows 11 (or Windows 10) machine, the very first launch of Weesper Neon Flow can fail with a Windows system popup appearing immediately at startup, before the main window has a chance to open. The popup typically says:
“The code execution cannot proceed because VCOMP140.DLL was not found. Reinstalling the program may fix this problem.”
(or, in localized Windows, the equivalent translated wording — for example in French: “Le programme ne peut pas démarrer car il manque VCOMP140.DLL sur votre ordinateur.”)
The application then closes.
This is caused by a missing Microsoft Visual C++ Redistributable — specifically the OpenMP runtime library VCOMP140.DLL, which is part of the Visual C++ 2015 runtime and is shipped by Microsoft inside the Visual C++ 2015–2022 Redistributable package.
Good news: this is fixed in less than two minutes by installing a small package directly from Microsoft.
Why This Happens
Weesper Neon Flow on Windows uses standard Microsoft C++ runtime libraries, including:
VCOMP140.DLL— the OpenMP parallel-computing runtime, used internally for fast on-device transcriptionMSVCP140.DLL,VCRUNTIME140.DLL— the core C++ runtime
These libraries are distributed by Microsoft through the Visual C++ Redistributable package.
On a typical Windows machine, the redistributable is installed by other applications (games, productivity tools, drivers). On a freshly installed Windows with very few apps, it can still be missing or older than the version Weesper Neon Flow expects. The result is an error dialog at launch instead of the application starting.
This is not a bug in Weesper Neon Flow and not a security issue. It is a Windows configuration that Microsoft itself recommends fixing by installing the redistributable.
How to Fix It — Step by Step
Step 1: Download the Microsoft Visual C++ Redistributable
Open the official Microsoft Learn page in your browser:
Download the file labeled vc_redist.x64.exe under the section “Visual Studio 2015, 2017, 2019, and 2022”. This single package is cumulative and covers every version Weesper Neon Flow needs.
Step 2: Install the Redistributable
- Locate the downloaded
vc_redist.x64.exefile (usually in your Downloads folder). - Double-click the file to start the installer.
- Accept the license terms and click Install.
- Wait for the installation to complete — it typically takes less than a minute.
- Click Close when finished.
In most cases a reboot is not required, but if Windows asks for one, accept it.
Step 3: Relaunch Weesper Neon Flow
Open Weesper Neon Flow from the Start menu. The error dialog should no longer appear. The application should now launch normally and display the main window.
If you see the error again, reboot your machine once and try a final time.
How to Confirm the Fix Worked
You can verify that the redistributable is now installed:
- Open Settings → Apps → Installed apps.
- Search for “Visual C++”.
- You should see at least one entry similar to “Microsoft Visual C++ 2015–2022 Redistributable (x64)”.
If the entry is present and Weesper Neon Flow still fails to launch, please contact our support team with the exact wording of the error dialog (title and body, copied as text) so we can investigate.
Why This Article Exists
This guide was created in May 2026 after a customer report on a freshly installed Windows 11 machine. The customer saw a Windows system popup at first launch indicating that VCOMP140.DLL was not found, and resolved the launch error by installing the Visual C++ Redistributable for Visual Studio 2015 (which is included in the cumulative 2015–2022 package above). The fix was confirmed working, so we are documenting it here to help anyone hitting the same symptom.
A pre-flight check that detects and installs the redistributable automatically is on our roadmap.
Related Guides
- How to Install Weesper Neon Flow — Complete installation guide for macOS and Windows
- System Requirements — Check hardware and OS compatibility
- Windows Security Warning (SmartScreen) — Handle the blue SmartScreen warning during install