Unable to start asp.net core web application in IIS Express

[EDIT] The problem was BitDefender Antivirus. I followed the instructions on how to install asp.net 5 beta 8. I was able to install all required files with no problem. However, every time I select the web template and try to run it with IIS Express, it loads for a few minutes and then displays the error: HTTP Error 502.3 - Bad Gateway... I tried all the troubleshooting steps in this guide and it didn't work success. I checked the event log and noticed the following two entries:

Invalid directory specified for caching compressed content C:\Users...Files\Clr4IntegratedAppPool. Static compression is disabled.

and:

The description for Event ID 1001 of the source HttpPlatformHandler could not be found. The component that caused this event is not installed on the local computer, or the installation is corrupted. You can install or repair components on your local computer.

If the event originated on another computer, the display information must be saved with the event.

The event includes the following information:

Process '4528' started successfully, listening on port 'x'.

I'm not sure if these warnings/infos are related to my problem. It would be good if someone could shed some light on this. All I know is that I have HttpPlatformHandler installed.

I decided to try another Visual Studio template (blank one), but oddly it works. Then I created a new web application and used the project properties and noticed that when I checked the checkbox: "Use Specific Runtime" and selected the x64 architecture, everything worked! :) However, I get the same old error if the checkbox is unchecked (the default), or if it is checked and the architecture is set to x86.

How can I run it with default settings? Or am I missing something here?

Here is my project.json file

{
  "webroot": "wwwroot",
  "userSecretsId": "aspnet5-WebApplication3-1a336a00-1f3e-432d-928e-f2669c4b0d94",
  "version": "1.0.0-*",

  "dependencies": {
    "EntityFramework.Commands": "7.0.0-beta8",
    "EntityFramework.SqlServer": "7.0.0-beta8",
    "Microsoft.AspNet.Authentication.Cookies": "1.0.0-beta8",
    "Microsoft.AspNet.Authentication.Facebook": "1.0.0-beta8",
    "Microsoft.AspNet.Authentication.Google": "1.0.0-beta8",
    "Microsoft.AspNet.Authentication.MicrosoftAccount": "1.0.0-beta8",
    "Microsoft.AspNet.Authentication.Twitter": "1.0.0-beta8",
    "Microsoft.AspNet.Diagnostics": "1.0.0-beta8",
    "Microsoft.AspNet.Diagnostics.Entity": "7.0.0-beta8",
    "Microsoft.AspNet.Identity.EntityFramework": "3.0.0-beta8",
    "Microsoft.AspNet.IISPlatformHandler": "1.0.0-beta8",
    "Microsoft.AspNet.Mvc": "6.0.0-beta8",
    "Microsoft.AspNet.Mvc.TagHelpers": "6.0.0-beta8",
    "Microsoft.AspNet.Server.Kestrel": "1.0.0-beta8",
    "Microsoft.AspNet.StaticFiles": "1.0.0-beta8",
    "Microsoft.AspNet.Tooling.Razor": "1.0.0-beta8",
    "Microsoft.Framework.Configuration.Abstractions": "1.0.0-beta8",
    "Microsoft.Framework.Configuration.Json": "1.0.0-beta8",
    "Microsoft.Framework.Configuration.UserSecrets": "1.0.0-beta8",
    "Microsoft.Framework.Logging": "1.0.0-beta8",
    "Microsoft.Framework.Logging.Console": "1.0.0-beta8",
    "Microsoft.Framework.Logging.Debug" : "1.0.0-beta8",
    "Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0-beta8"
  },

  "commands": {
    "web": "Microsoft.AspNet.Server.Kestrel",
    "ef": "EntityFramework.Commands"
  },

  "frameworks": {
    "dnx451": { },
    "dnxcore50": { }
  },

  "exclude": [
    "wwwroot",
    "node_modules"
  ],
  "publishExclude": [
    "**.user",
    "**.vspscc"
  ],
  "scripts": {
    "prepublish": [ "npm install", "bower install", "gulp clean", "gulp min" ]
  }
}

Since then I have been trying the following:

1. Start Visual Studio in Safe Mode.
2. Cleared the Visual Studio cache.
3. Fixed Visual Studio 2015.
4. Uninstall and then reinstall Visual Studio 2015.
5. Completely formatted my PC and reinstalled.

Some other information:

• I am running Windows Enterprise 10.
• I am running Visual Studio 2015 Enterprise Edition.
• It's worked once or twice, but I can't tell when any patterns appear.
• I just want Visual Studio ASP.net 5 MVC to run templates out of the box.
• I tried different BETA versions as well as RC versions.