Site opens but does not load Cs, js, png files etc

Question

I migrated VS2012 to VS2017, and in my solution I have 3 sites, 2 of which I run and have no problem and in the other when I debug it opens but the whole part of Design is not loaded(css, js, png, etc). Seeing the page log in Fiddler I have 2 errors that are them

1) IIS 10.0 Detailed Error - 500.19 - Internal Server Error

2)

This error occurs when there is a problem Reading the Configuration file for the Web server or Web application. In some cases, the Event logs may contain more information about what caused this error.

If you see the text "There is a Duplicate 'system.web.Extensions/scripting/scriptResourceHandler' Section defined", this error is because you are running a . NET Framework 3.5-based application in . NET Framework 4. If you are running Webmatrix, to resolve this problem, go to the Settings Node to set the . NET Framework version to ". NET 2". You can also remove the extra sections from the web.config file.

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Someone knows how to fix this. I’ve been around for 2 days and I haven’t found a solution.

Answer 1

I found the solution to my problem. I had to remove the following code from Web.config

 <staticContent>
  <mimeMap fileExtension=".json" mimeType="application/json" />
</staticContent>