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

User · Accepted Answer

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.

User · Answer

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

User · Answer

In Debug   Website Properties   change port number in Project Url to any nearest value and save

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

Simply start your Visual Studio as Run as Administrator  Thanks

User · Answer

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

User · Answer

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

User · Answer

I was changing this entry  for which my web server was not running and showing me access denied error for a particular port    lt bindings gt      lt binding protocol  http  bindingInformation    61235 localhost    gt   lt  bindings gt    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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

So after trying all the solution  I just uninstall  One Drive  from my PC  amp  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

User · Answer

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

User · Answer

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

User · Answer

Remove the default website from the  lt sites gt   lt  sites gt    lt site name  WebSite1  id  1  serverAutoStart  true  gt       lt application path     gt           lt virtualDirectory path     physicalPath   IIS SITES HOME  WebSite1    gt       lt  application gt       lt bindings gt           lt binding protocol  http  bindingInformation   8080 localhost    gt       lt  bindings gt   lt  site gt    and your own  lt site gt   lt  site gt    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

User · Answer

If using VS2015  close the solution  delete the following file  then re-open the solution    lt  lt path to solution folder gt  gt   vs config applicationhost config   note the  vs folder may be hidden

[asp.net] "Unable to launch the IIS Express Web server" error

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