Unable to start debugging | Visual studio 2015

Question

I've recently reinstalled win 10 on my pc (so the system is clean now) and when i try to start my asp project even the default one with or without debugging the following error appears -

Unable to start debugging. Operation not supported. Unknown error: 0x80070057

Screenshot. I tried to reinstall visual studio 2015 community update 3, IIS (Program and feature option) and IIS Express. Nothing helps.

Answer 1

I almost tore my hair out trying to figure what was wrong - cleaned project, rebooted, cleaned out user folder, deleted virtual directory in IIS - nothing worked.

Turned out in my case it was some misspelled nodes in the web.config file.

Specifically I had:

<system.webServer>
    ..
    <httpprotocol>
      <customheaders>

instead of:

<system.webServer>
    ..
    <httpProtocol>
      <customHeaders>

Fixed that and problem solved.

Also, had to remove the following (content-type) otherwise the error returned. Not sure if it was a valid setting anyway...

<httpProtocol>
  <customHeaders>
    ..
    <add name="Content-Type" value="application/json"/>

Answer 2

Hmm. A solution to this problem was very odd. In visual studio i created a new asp core template project and ran it. As usual i got an error message but this time something like iis cant connect to the local machine due to naming conflict. In system properties my computer description field was exactly like the computer name. So i cleared it. The problem gone.

Answer 3

In my case, it was visual studio community 2017. The web project was set to launch the web app with the internal browser.

Once I started the project in any other standard browsers (Chrome, Internet Explorer, Firefox, etc.) I could run the app and debug.

Hope this can be of help to someone!