"Unable to launch the IIS Express Web server" error

Question

I receive this error when trying to launch IIS Express from Visual Studio with a project that's configured to listen to an address other than localhost. Visual Studio freezes for about 30 seconds before giving the error "Unable to launch the IIS Express Web server".

I've tried all the solutions posted to similar questions and I think I've done everything correctly. Here are the steps that I have taken:

Add the following reservation to HTTP.SYS:

netsh http add urlacl url=http://+:36899/ user=Everyone
Run Visual Studio 2012 as an administrator (technically I don't think I should even have to since I set up HTTP.SYS manually).
Disable Windows Firewall.
Delete my IISExpress folder in my My Documents folder to ensure the default settings.
Allow Visual Studio to create the entry in applicationhost.config for my web project. Then manually edit the config file to change localhost to 192.168.0.100 which is my local IP. Then go back into the project properties in Visual Studio and change localhost to the IP and save the project so that my project is now set to http://192.168.0.100:36899.

I also tried changing the port and repeating the above steps just incase the port was in use for some reason.

I want to make my IIS Express developer instance accessible from my IP on the Internet for remote testing.

Creating a [virtual directory](http://stackoverflow.com/a/34161146/2404470) solved the problem for me. — Zameer Ansari, Dec 08 '15 at 16:37

score 63 · Answer 1 · edited Dec 12 '17 at 10:58

63

If using VS2015, close the solution, delete the following file, then re-open the solution.

<<path_to_solution_folder>>\.vs\config\applicationhost.config

note the .vs folder may be hidden

edited Dec 12 '17 at 10:58

Ibrahim Dauda

645
8
19

answered Sep 28 '16 at 07:32

Hemant Jain

631
5
4

This works a treat, and it's a far better solution than messing with (or nuking) your IISExpress configuration as other answers suggest. – Daniel Liuzzi Mar 27 '17 at 03:26
1

Let me add something that is implicit. Delete this file before opening/loading the solution. – Luis Lavieri May 09 '17 at 13:35
@Luis makes a valid point. Solution needs to be closed before the applicationhost.config file is deleted. – Ibrahim Dauda Dec 12 '17 at 07:02
those people who didn't find the folder, enable the hidden folder show option, it will shown after that. – Anirudha Gupta Jun 04 '18 at 06:16
Unfortunately there is no .vs folder in my project. (not even hidden folder)... I've VS2012. Any other solution??? – Ahsan Arshad Dec 24 '18 at 08:12
This and the pending "update and restart" was actually breaking me. Upvoting this again! Thank you – Alex Sorokoletov Dec 12 '19 at 03:03

Trevor Elliott · Accepted Answer · 2013-08-30T16:28:27.947

51

The one thing that fixed this for me was using the following line in the <bindings> section for my site in the applicationhost.config file:

<bindings>
    <binding protocol="http" bindingInformation="*:8099:" />
</bindings>

The key was to simply remove localhost. Don't replace it with an asterisk, don't replace it with an IP or a computer name. Just leave it blank after the colon.

After doing this, I don't need to run Visual Studio as administrator, and I can freely change the Project Url in the project properties to the local IP or computer name. I then set up port forwarding and it was accessible to the Internet.

EDIT:

I've discovered one more quirk that is important to getting IIS Express to properly serve external requests.

If you are running Visual Studio/IIS Express as an administrator, you must not add a reservation to HTTP.SYS using the "netsh http add urlacl ..." command. Doing so will cause an HTTP 503 Service Unavailable error. Delete any reservations you've made in the URLACL to fix this.
If you are not running Visual Studio/IIS Express as an administrator, you must add a reservation to the URLACL.

edited Aug 30 '13 at 16:28

answered Aug 27 '13 at 03:16

Trevor Elliott

11,292
11
63
102

3

Great tip! In my case, this helped too: http://blogs.msdn.com/b/finbar_ryan/archive/2013/01/02/debugging-the-unable-to-launch-the-iis-express-web-server-error-from-visual-studio-2012.aspx – deerchao Dec 21 '13 at 13:27
Worked for me, but only after I restarted Visual Studio too. – Richard Fawcett Mar 07 '14 at 10:55
3

Trevor you saved my life. I was close to quit programming and become a farmer. Took me so long to get this fixed but the "just blank after colon" trick saved me. Anyway one more thing, for me i still needed to add the URLACL reservation, since otherwise I would get "Failed to register URL "http://*:62940/" for site "SITE NAME" application "/". Error description: Access is denied. (0x80070005)." Needed to add exactly that to ACL list. Thank's god it works now. – skhro87 Sep 19 '14 at 07:24
2

When you change this for IIS Express you need to run visual studio in Admin mode. if not, IIS Express won't start up. – Stefanvds Jul 25 '15 at 03:38
This works but fails when my project URL is pointing to a different hostname other than localhost when loading the project. I made some instructions here to achieve https://gist.github.com/sydcanem/30c16b414bc47694d2ce. – James Jan 16 '16 at 06:12
Can anyone direct me to instructions on how to find out what i recently added using the NetSh command, i we reading other SO posts and several has me run netsh commands and I cant' find the links. I'm now only able to run non admin in vs2019 Thanks – Eric Brown - Cal Oct 01 '20 at 18:40

score 31 · Answer 3 · answered Nov 18 '13 at 04:24

31

I had exactly the same issue. Tried everything but finally one trick worked.

Delete folder IISExpress from "My Documents"
Load your project again, it will create IISExpress folder again with updated configuration
Check IISExpress folder has sufficient permissions to read-write the configuration file
Load project again and Run IISExpress. It should work.

answered Nov 18 '13 at 04:24

Sumit Bajaj

327
3
3

This worked for me! My "My Document" dir is on our fileshare, so when I switched from an old PC to a new one, my VS projects loaded just fine, but got the generic "Unable to launch the IIS Express Web server" error when I tried to run the app. Deleting and re-running the project fixed the issue for me. – ewitkows Jan 20 '15 at 16:04
Didn't have exact same error but IIS related functionality (creating a new MVC project, launching a web site, and so on) kept giving errors . I had an IISExpress folder under Documents from a previous system installation with both VS and WebMatrix installed. Deleting the entire folder seems to have fixed all my issues. VS created a fresh new IISExpress folder. – Protongun Jan 27 '15 at 07:40
Not for me. So far only solution is to reboot the machine. – Patrick Borkowicz Jan 21 '16 at 20:04
VS2013, same issue. Just the step#1 solved it for me! – Vin May 11 '17 at 17:18
Thanks. Only this fix resolved my issue. Buggy Microsoft as usual filled with undeserved people in their core. – vibs2006 Sep 20 '22 at 08:55
Thanks buddy. This worked for me finally after struggling for almost 2hrs. Make sure to take a back up of IISExpress folder for safety. – Shantilal Suthar Jan 31 '23 at 11:51

score 14 · Answer 4 · answered Aug 12 '17 at 14:45

Close your project.
Go to folder settings and select show hidden folders option.
Open the folder where your application is. You will see a .vs folder.
Open the .vs folder, you will see a config folder in it. Delete its content.
Run Visual Studio in admin mode. Open your solution from the File menu.
Clean your solution.
Build it.
Run it and voila!

I do not recommend deleting IIS Express folder or messing with the config file in it.

score 10 · Answer 5 · edited Feb 28 '14 at 20:02

I was changing this entry (for which my web server was not running and showing me access denied error for a particular port)

<bindings>
   <binding protocol="http" bindingInformation="*:61235:localhost" />
</bindings>

in the "applicationhost.config" in "Documents\IISExpress\config" for a particular webapplication it was overwritten by Visual Studio 2012 again to default port whenever I was starting my webapplication.

But I resolved the problem by doing nothing in the applicationhost.config. I just changed the "project properties" > "web" > "project url" setting from http://localhost:62135/ to http://localhost:47279/(depends on your computer) and it worked for me.

score 7 · Answer 6 · edited Jun 30 '16 at 09:50

7

Try this:

Open Properties of your solution
Go to web
under LOCAL IIS, Change written port number to any other port number and create a new virtual directory.

edited Jun 30 '16 at 09:50

Bahtiyar Özdere

1,818
17
21

answered Jun 17 '16 at 06:43

Raja

451
5
5

This did the trick for me! Modifying/deleting applicationhost.config did not work, but a simple change of the port did. Note: I only experienced the problem when running "Start without debugging (CTRL+F5). – Lars Peter Larsen Jun 09 '20 at 07:53

score 6 · Answer 7 · answered Dec 13 '17 at 04:47

6

Simply start your Visual Studio as Run as Administrator

Thanks,

answered Dec 13 '17 at 04:47

Nimesh

3,342
1
28
35

score 5 · Answer 8 · answered Nov 05 '13 at 09:05

5

I had the same issue, but with a different cause that may help others.

Use a commandprompt in admin mode for this: - TYPE: netsh http show iplisten If there are any IP entries: - TYPE: netsh http delete iplisten Repeat until the list is empty. Check if IIS Express starts now.

Hope this helps, Niels

answered Nov 05 '13 at 09:05

Niels Bos

61
1
1

I been struggling with this for 15 hours. finally this solved my issue. thank you very much!!!!! – NAS Mar 19 '17 at 04:31

score 5 · Answer 9 · edited Feb 14 '14 at 13:13

5

Deleting the unnecessary site entries from applicationhost.config file solved the issue for me.

edited Feb 14 '14 at 13:13

Kira

1,153
4
28
63

answered Feb 14 '14 at 12:55

user3310307

51
1
1

score 4 · Answer 10 · answered Jun 15 '17 at 08:19

For me it was the applicationhost.config file in .vs folder in my project solution folder(.vs folder is hidden by default).So,I closed the project and delete the .vs folder (vs will recreate it again when you open the project) then reopen the project and run it.

score 2 · Answer 11 · edited Apr 08 '15 at 12:41

2

In my case i tried following things to fix this problem.

Delete the iisexpress folder from "MyDocuments"
Go to Solution Explorer --> Right click on the Project --> Go to Properties --> Go to Web tab --> See the Servers --> click on radio button "USe Visual Studio Developtment Server"

I hope this will help you.

edited Apr 08 '15 at 12:41

Mario Levrero

3,345
4
26
57

answered Dec 03 '14 at 04:27

Sunny

2,183
1
17
13

score 2 · Answer 12 · answered Feb 16 '16 at 19:05

I fixed it with the following steps:

Close Visual Studio
Run netsh http show urlacl and see if your application http address/port is listed.
Run netsh http delete urlacl url=[ADDRESS] replacing [ADDRESS] with the Reserved URL shown by the previous command. For example http://+:17560/
Run VS again (as Admin) then go to web project's Properties -> Web then click on Create Virtual Directory button.
Now you should be able to run the web project.

score 1 · Answer 13 · answered May 16 '16 at 12:20

1

In Debug > Website Properties.

change port number in Project Url to any nearest value and save

answered May 16 '16 at 12:20

user3501613

596
7
28

Visual Studio 2019 Web Project after Win 10 Upgrade and the above is the correct way to resolve. – CraigJSte Jul 06 '20 at 23:40

score 1 · Answer 14 · answered Feb 21 '17 at 23:54

1

I spent 1 hour trying every recipe mentioned above. Then out of no where I restarted my computer, and tried again. And everything is fine now.

So please try restarting your computer before trying all the above mentioned solutions. It might help

answered Feb 21 '17 at 23:54

Tajveer Singh Nijjar

495
6
18

score 0 · Answer 15 · answered Feb 14 '14 at 11:51

I had the same problem with Visual Studio 2012. I managed to resolve it by removing from C:\Program Files (x86)\IIS Express\AppServer\applicationhost.config path unneccessary site entries. Alongwith running my VS2012 as an Administrator. Hope this helps

score 0 · Answer 16 · answered Jun 26 '15 at 08:33

0

At the start, Try to disable your firewall. It helped me. The Eset Smart Security 5 blocked it.

answered Jun 26 '15 at 08:33

user3205810

83
2

score 0 · Answer 17 · answered Jul 11 '15 at 16:56

I had this problem some days ago and all of above items could not help me. I have ESET Smart Security 5.0 on my SONY VAIO laptop which works in interactive mode! Finally I found the problem, ESET was blocking VS2012! In the past, ESET had asked me to allow the VS2012 to communicate with Microsoft, I had chosen "Deny Access" and ESET had mad a rule for denying VS2012. I omitted this rule from "ESET rules zone" and my issue was solved!

score 0 · Answer 18 · answered Sep 27 '15 at 06:12

0

Delete IISExpress folder in my My Documents folder to ensure the default settings or restore the same to previous version when it was working fine.

answered Sep 27 '15 at 06:12

Elvis

29
6

score 0 · Answer 19 · edited Sep 29 '15 at 19:22

Remove the default website from the <sites> </sites>

<site name="WebSite1" id="1" serverAutoStart="true">
    <application path="/">
        <virtualDirectory path="/" physicalPath="%IIS_SITES_HOME%\WebSite1" />
    </application>
    <bindings>
        <binding protocol="http" bindingInformation=":8080:localhost" />
    </bindings>
</site>

and your own <site> </site>

and run "C:\Program Files\IIS Express\iisexpress.exe"

http://www.iis.net/learn/extensions/using-iis-express/running-iis-express-from-the-command-line

score 0 · Answer 20 · answered Jan 27 '16 at 21:34

0

In VS 2013 I saw this error after setting up Google Docs synchronization on My Documents. Updated permissions to not be read-only and problem solved.

answered Jan 27 '16 at 21:34

Rick Putnam

546
1
6
20

score 0 · Answer 21 · answered Nov 12 '16 at 10:30

open command prompt as administrator then execute this command :

netsh http show urlacl

you will see the url you have added before now you should execute this command :

netsh http delete urlacl url=http://+:36899/ user=Everyone

please check the url from list when using :

(netsh http show urlacl)

score 0 · Answer 22 · answered Nov 21 '17 at 12:18

0

I face this issue, All I did was go to the web project Properties -> Web -> In the ProjectUrl I clicked on the "Create Virtual Directory" and my issue was fixed.

answered Nov 21 '17 at 12:18

Willy

3,506
3
22
35

score 0 · Answer 23 · edited Dec 06 '17 at 16:55

0

I had the same issue with my computer having loads of windows updates.

Spent few hours trying to resolve the issue using above answers with no luck.

In past we have different issues due to anti-virus which caused the application to be blocked by it, so thought to try by disabling it.

edited Dec 06 '17 at 16:55

Hille

2,123
22
39

answered Dec 06 '17 at 13:25

varun

54
1
7

score 0 · Answer 24 · answered Jan 16 '19 at 17:28

0

So after trying all the solution, I just uninstall "One Drive" from my PC & the problem is resolved.

N.B:

I was trying to run .net core web application.
Visual Studio 2017 version 15.9.5
Windows 10 Pro, 64 bit

answered Jan 16 '19 at 17:28

Biswajit Panday

817
10
20

score 0 · Answer 25 · answered Feb 14 '19 at 07:00

0

Click the Solution and press F4. Then match the port from Right-click on solution and select Properties to the web tab port. The port no will be the same of both case F4 and Properties.

answered Feb 14 '19 at 07:00

Abhishek Kanrar

418
4
6

score 0 · Answer 26 · answered Jan 27 '21 at 12:58

0

Tried deleting IISExpress folder, changed port , restart VS and PC but it didn't work. However it worked after killing iisexpress.exe service in services.

answered Jan 27 '21 at 12:58

Paresh Patil

1

score 0 · Answer 27 · edited May 29 '21 at 08:06

0

change the parameter in the registry

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HTTP

parameter Start from 4 to 3 and reboot

edited May 29 '21 at 08:06

Grigory Zhadko

1,484
1
19
33

answered May 26 '21 at 08:58

Виктор Шевчук

1
1

2

Please add an explanation of why, and how, this works. Thank you. – JustCarty May 26 '21 at 16:45

"Unable to launch the IIS Express Web server" error

27 Answers27

Linked