If you’re getting this Visual Studio error: Process with an Id of ### # is not running. It usually means IIS Express (or the Visual Studio debug process) has crashed or stopped unexpectedly while Visual Studio is still attached. This isn’t an application code issue — it’s a runtime or IDE glitch . Here’s how you can fix it quickly 👇 1. Stop All IIS Express Processes Close the browser and stop debugging ( Shift + F5 ). Open Task Manager → Details tab. End all processes named: iisexpress.exe Once done, restart debugging ( F5 ). 2. Delete IIS Express Temporary Config Sometimes a corrupted configuration file causes this problem. Navigate to: %USERPROFILE%\Documents\IISExpress\config Rename or delete the file: applicationhost.config Visual Studio will automatically recreate it when you start debugging again. 3. Clean and Rebuild Your Project In Visual Studio: Build → Clean Solution Build → Rebuild Solution This ensures any leftover temporary build data is re...