How do I resolve "HTTP Error 500.19 - Internal Server Error" on IIS7.0 [closed]
I had the same issue, but reason was different.
In my web.config there was a URL rewrite module rule and I haven’t installed URL rewrite module also. After I install url rewrite module this problem solved.
Looks like the user account you're using for your app pool doesn't have rights to the web site directory, so it can't read config from there. Check the app pool and see what user it is configured to run as. Check the directory and see if that user has appropriate rights to it. While you're at it, check the event log and see if IIS logged any more detailed diagnostic information there.
On Windows 10 I had to install ASP.NET 3.5 and ASP.NET 4.6 under Internet Information Services (the other boxes automatically check themselves):
