VS2010 error: Unable to start debugging on the web server

Question

I get error message "Unable to start debugging on the web server" in Visual Studio 2010. I clicked the Help button and followed the related suggestions without success.

This happens with a newly created local ASP.Net project when modified to use IIS instead of Cassini (which works for debugging). It prompts to set debug="true" in the web.config and then immediately pops up the error. Nothing shows up in the Event Viewer.

I am able to attach to w3wp to debug. It works but is not as convenient as F5.

I also have a similar problem with VS2008 on the same PC. Debugging used to work for both.

I have re-registered Framework 4 (aspnet_regiis -i). I ran the VS2010 repair (this is the RTM version). I am running on a Windows Server 2008 R2 x64 box.

I do have Resharper V5 installed.

There must be some configuration setting or registry value that survives the repair causing the problem.

I'd appreciate any ideas.

Thanks, Gary Davis ([email protected])

Answer 1

You can firstly deploy your web application/site with your iis, then open your visual studio 2010. Then click "File"->open->website->Local IIS Site, then select your website/application. Then you will find that the debug may works. This method works for my case.

Answer 2

I don't have a definite answer though these articles may have some helpful info:

Using Windbg to start with w3wp.exe This mentions windbg/cdb debuggers specifically, but this advice should work with Visual Studio talking to cdb (which is attached to w3wp).

Remote debugging with Visual Studio The reason I mention remote debugging at all is that I had to use that a few times in the past to get Visual Studio to attach to w3wp.exe. W3wp.exe runs in a different session, so you can't directly attach a debugger to that.

Answer 3

You have not mentioned what operating system you are using. But this might not be related to operating system. I am taking a guess here. If you are running on Windows 7, try running visual studio under Administrator previlages.

You can also try adding your user ID to the VS debugger users group. You can access user groups by reight clicking on computer name or my computer and selecting Manage. Under that you can find Users & Groups.

Answer 4

Disable the loopback check

(original microsoft page here)

To set the DisableLoopbackCheck registry key, follow these steps:

Click Start, click Run, type regedit, and then click OK.

In Registry Editor, locate and then click the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa

Right-click Lsa, point to New, and then click DWORD Value.

Type DisableLoopbackCheck, and then press ENTER.

Right-click DisableLoopbackCheck, and then click Modify.

In the Value data box, type 1, and then click OK.

Quit Registry Editor, and then restart your computer.

Answer 5

Your solution file in visual studio is broken. It's a known issue when converting from a file-system website to an IIS website, and it has been carried over from 2008 to 2010. Not sure of the location for the bug report on ms's kb site, though.

Remove the website from the solution file (right click the project name, click "remove"). Then right click the solution name, click "add existing web site". When the dialog to add a web site comes up, choose "from IIS" in the left-hand pane. Navigate to your application in IIS, select "use secure sockets layer" if necessary, and click "finish" (or whatever that button is labeled).

this will permanently fix the issue.

Answer 6

In IIS in the Directory Security TAB, if using SSL check "Ignore client certificate" if you are running it in your local PC.