C#: ASP.NET 5 MVC: Unable To Connect To Web Server ‘iis Express’

There can be several reasons why you might be unable to connect to the IIS Express web server in ASP.NET 5 MVC. Here are a few suggestions to troubleshoot the issue:

  1. Make sure IIS Express is installed: Ensure that you have IIS Express installed on your machine. You can check this by searching for "IIS Express" in your start menu and verifying that it shows up.

  2. Check IIS Express settings: Open your project’s launchSettings.json file located under the Properties folder. Ensure that the sslPort is set to a valid and available port number. Also, check if the applicationUrl matches the correct URL format for your project.

  3. Restart IIS Express: Sometimes, IIS Express can encounter issues and fail to start properly. Try restarting IIS Express by closing any instances of it and re-running your project.

  4. Check for conflicting applications or services: Make sure that no other applications or services are running on the same port that your project is configured to use. You can use the netstat command in the command prompt to check for any conflicts.

  5. Check firewall settings: Ensure that your firewall is not blocking the connection to IIS Express. You may need to add an exception or rule in your firewall settings to allow the communication.

  6. Verify project configuration: Check if your project’s configuration files (appsettings.json, web.config, etc.) are properly configured and match the requirements of your MVC application.

  7. Rebuild the project: Sometimes, a build issue can prevent the project from running properly. Try rebuilding your project by right-clicking on the project in Visual Studio and selecting "Rebuild" or by running the dotnet build command.

  8. Update Visual Studio: If you are using an older version of Visual Studio, consider updating it to the latest version. Newer versions often include bug fixes and improvements that can help resolve such issues.

If none of the above suggestions work, it may be helpful to provide more specific details about the error or any additional error messages you are encountering.

About the Author Rex

I'm a passionate tech blogger with an insatiable love for programming! From my early days tinkering with code, I've delved into web dev, mobile apps, and AI. Sharing insights and tutorials with the world is my joy, connecting me to a global community of like-minded tech enthusiasts. Python holds a special place in my heart, but I embrace all challenges. Constantly learning, I attend tech conferences, contribute to open-source projects, and engage in code review sessions. My ultimate goal is to inspire the next generation of developers and contribute positively to the ever-evolving tech landscape. Let's code together!