Unable to connect webserver 'IIS Express'

Question

I changed my launch setting to support remote IP hosting:

{
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://192.168.1.69:55446/",
      "sslPort": 0
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "myapplication": {
      "commandName": "Project",
      "launchBrowser": true,
      "launchUrl": "http://localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

It works well in my system.

Ihen I download my project from TFS in another remote system and changed the ipaddress to support remote ip hosting and run the application in adminstrator mode. But still it showing "Unable to connect webserver 'IIS Express'"

 {
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://192.168.1.79:55446/",
      "sslPort": 0
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "eBMSForumApplication": {
      "commandName": "Project",
      "launchBrowser": true,
      "launchUrl": "http://localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

I don't know exactly what's wrong in your situation, but another solution might be to use our free VS Extension called Conveyor -> https://visualstudiogallery.msdn.microsoft.com/a429dbb7-a982-4541-b401-934375c02c0f?redir=0 it allows connections to IIS Express from other machines/devices. — Jim W, Jan 26 '17 at 18:00
@raj, did you ever find out the cause of this? I have asked a similar question here today: https://stackoverflow.com/questions/56890385/create-binding-causes-unable-to-connect-to-web-server-iis-express. Thanks. — w0051977, Jul 04 '19 at 15:19
for me it was port issue i changed the port issue in the applicationUrl launch settings.json and it worked — Rahul Sharma, Oct 16 '19 at 08:49

score 16 · Answer 1 · answered Jan 20 '21 at 07:34

If you see something like this in the output console:

IIS Express starting...
iis express Failed to register URL "http://localhost:61367/" for site application "/". 
Error description: The process cannot access the file because it is being used by 
another process

The error is due to the port you are using.

Open a console and check out used port ranges with this command:

netsh interface ipv4 show excludedportrange protocol=tcp

It will look like this:

Change the port number you wanna use, which is outside of those ranges.

score 5 · Answer 2 · answered Aug 04 '21 at 23:45

5

This problem is similar to https://stackoverflow.com/a/67990888/733760 and could be related to Hyper-v reserving a bunch of port ranges.

If that's the problem, the same answer applies (and worked for me). Run as admin:

net stop winnat
net start winnat

answered Aug 04 '21 at 23:45

AlexDev

4,049
31
36

Make sure to exit IIS Express in the command tray and then run the above command. – shammelburg Sep 22 '21 at 07:50

score 2 · Answer 3 · answered Mar 26 '21 at 09:16

In my case, I unchecked "Enable SSL" in debug from project properties and ran the project. It made an iis pop up to appear which said the port is being used by chrome. So I closed all instances of chrome and switched again to "Enable SSL" and it fixed my issue.

score 2 · Answer 4 · edited May 04 '21 at 17:42

2

The same thing happened but I don't know the reason, I restarted IIs and VS which didn't work. Then I restarted the computer, it is all fixed.

edited May 04 '21 at 17:42

kiyah

1,502
2
18
27

answered May 03 '21 at 23:01

Alison Niu

64
3

score 1 · Answer 5 · answered Dec 15 '20 at 15:05

1

In my case, I had modified the project url in the debug mode, and after that it failed to run, I had to restart my Visual Studio in order to get it working.

answered Dec 15 '20 at 15:05

Jamshaid K.

3,555
1
27
42

score 0 · Answer 6 · answered Aug 21 '20 at 07:47

I also encountered this issue recently (along with some others: VS 2019 does not open web app project in chrome if chrome is already open) and found out that I was running VS in administrator mode.

I resolved this by running VS and Chrome in normal mode.

score 0 · Answer 7 · answered Jun 30 '21 at 04:33

0

my project version 2.2 my computer version 5.0 (cmd: dotnet --list-sdks)

I installed version 2.2 to my computer. I can run the application now.

answered Jun 30 '21 at 04:33

Nguyễn Xuân Hoàng

582
7
23

score 0 · Answer 8 · answered Aug 09 '23 at 07:21

0

I tried all suggested solutions but for me the only solution is to go cert store delete my dev certificate (localhost) and solved.

answered Aug 09 '23 at 07:21

aydoğdu demirci

13
5

Unable to connect webserver 'IIS Express'

8 Answers8