How do I resolve missing DLL errors caused by incorrect DLL probing paths?

Probe Path Confusion

Your executable lives in a subfolder, yet the runtime cannot locate a required assembly. The default probing path only checks the application base directory, which is why you see a FileNotFoundException at runtime.

Configuring explicit paths

Edit your app.config or web.config and add a probing element under runtime. This tells the CLR exactly where to look.

<!-- Specify additional private bin paths for assembly resolution -->
<configuration>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <probing privatePath="bin\libs" />
    </assemblyBinding>
  </runtime>
</configuration>

• Keep third-party dependencies in a dedicated folder, not scattered across the project root.
• Ensure the privatePath is relative to the application base.
• Validate the folder permissions match the account running the process.