Why is IIS Express returning HTTP 500 errors loading javascript and CSS?

Question

I am trying to develop an ASP.NET MVC5 solution using IIS Express for local debugging. Frequently, Chrome will report HTTP500 errors trying to load certain JS and CSS files (so

Answer 1

What helped worked is as follows. I am using Visual Studio 2015.

1. Close the visual studio solution. In fact I closed the visual studio itself
2. In the solution folder(the folder which contains the .sln file along with the project folders), you should find a .vs folder. I had deleted that folder.
3. Restarted the visual studio and loaded the solution.

Things are working fine now.

The reason I guess is, the config folder inside of .vs folder has the applicationhost.config file. That is having some setting issues.

Answer 2

In my case, I got to remove the attribute of debug="true" in web.config compilation node.

From

<compilation debug="true" targetFramework="4.7.2" />

To

<compilation targetFramework="4.7.2" />

Then it works fine.

Answer 3

Turns out this was related to ninject object lifecycles and my EF db context being open twice at the same time. Totally unrelated to IIS.