"Cannot start debugging on Web server" error

If you encounter these errors, consider the following:

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Web applications on remote serversProgram
Web applications stored in visual sourcesafe and extended by Frontpage servers
Manually attach
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If the error "cannot start debugging on the Web server" is returned, check the following:

Are you running a Windows version that allows Visual Studio debugger to automatically attach to a web application? If not, start the application without debugging and manually attach it. (For more information, see manually attaching and ASP. NET debugging: system requirements .)
Does your web application have a web. config file?
Does the Web. config file enable the debugging mode by setting the debug attribute to true? For more information, see debug mode in ASP. NET applications.
Does web. config contain any syntax errors? You can run a web application without debugging to check for syntax errors. (Select "start execution (not debugging)" from the "debug" menu )".) If a syntax error exists in Web. config, the detailed information is displayed.
Are you a member of the debugger Users Group? If you log on as an administrator, is the administrator in this group?
Have you created a project by specifying a specific IP address (for example, 100.0000300.400? NTLM authentication is required for Web Server debugging. By default, the IP address is assumed to be part of the Internet, and NTLM authentication is not performed on the Internet. To correct this problem:
When creating a project, specify the name of the computer on the Intranet.
-Or-

Add the IP address (http: // 100.0000300.400) to the list of trusted sites on your computer. (Select "Internet Options" from the "Tools" menu of Internet Explorer, and then select the "Security" tab ).
Does the computer running the IIS server have the Visual Studio. NET remote component installed?
Is IIS installed on a local computer (that is, a computer running Visual Studio. NET) after Visual Studio. NET is installed? IIS should be installed before Visual Studio. NET is installed. If it is installed later, you may need to repair the. NET Framework.
Fix. NET Framework

Insert and run the Visual Studio. NET Disc
: \ WCU \ dotnetframework \ dotnetfx.exe/T: C: \ Temp/C: "msiexec.exe/fvecms c: \ temp \ netfx. MSI"
-Or-

Insert and run the Visual Studio. NET Windows component update CD.

: \ Dotnetframework \ dotnetfx.exe/T: C: \ Temp/C: "msiexec.exe/fvecms c: \ temp \ netfx. MSI"
Is the URL of the project start page specified correctly? Is the extension and project directory correct?
Is IIS Security Settings correctly set? To verify this, check the "Default web site" settings.
Check IIS security settings for "Default web site"

Select programs and administrative tools from the Start menu, and then click Internet Service Manager (Windows 2000) or Internet Information Service (Windows XP ).
In the Internet Service Manager or Internet Information Service dialog box, click tree control on your computer ). In the "web site" folder, find "Default web site ".
Right-click "Default web site" and select "properties ".
In the "Default web site properties" window, select the "Directory Security" tab and click "edit ".
In the "authentication method" dialog box, select "Anonymous Access" and "Integrated Windows Authentication" (if not selected ).
Click OK to close the Internet Service Manager or Internet Information Service dialog box.
Click OK ".
For the ATL server application, verify that the debug predicate is associated with your ISAPI extension.
For ASP. NET applications, make sure that the virtual folder of the application has the "Application name" set in "Internet Service Manager" or "Internet information service ".
Specify virtual folders for Web Applications

Select programs and administrative tools from the Start menu, and then click Internet Service Manager (Windows 2000) or Internet Information Service (Windows XP ).
In the Internet Service Manager or Internet Information Service dialog box, click tree control on your computer ). Find the web application in the Web site folder.
Right-click "Default web site" and select "properties ".
In the "Default web site properties" window, select the "directory" tab.
Under "application settings", click "CREATE ".
The Application name appears in this box.

Click OK to close the Properties dialog box.
Click OK to close the Internet Service Manager or Internet Information Service dialog box.
Web applications on remote servers
If the web application is on a remote server, check the following:

Have you run the correct installer to install ASP. NET/ATL server and remote debugger components on the server?
Are you a member of the debugger Users Group on the server? Do you have the access privileges necessary to debug processes running under the system account?
Depending on the security settings, ASP. NET applications may run in inetinfo.exe (IIS Process) or ASP auxiliary process aspnet_wp.exe. The aspnet_wp.exe process runs as a system. To debug an application running under aspnet_wp.exe, you must have the administrator privilege or edit the machine. config file for aspnet_wp.exe so that aspnet_wp.exe can run under your account. To debug an application running in inetinfo.exe, you must be an administrator on the computer running inetinfo.exe.

Depending on the security settings, the ATL server application may run under inetinfo.exe or the ATL auxiliary process dllhost.exe. To debug an application running in inetinfo.exe, you must be an administrator on the computer running inetinfo.exe, or use the Common Language Runtime Library application to configure DLLHOST to run as a specific user.
Are you using "Terminal Server" to try to debug Web applications on a remote computer? In Windows XP, remote debugging of Local Web applications can be performed using terminal servers. Not supported in Windows 2000 or Windows NT.
Web applications stored in visual sourcesafe and extended by Frontpage servers
If a web application is stored in visual sourcesafe and uses the FrontPage Server Extension as its web access mode, check the following:

Is visual sourcesafe on the same computer as the FrontPage Server or web server? If yes, you can use integrated authentication for debugging. (To check the "Integrated authentication" Settings, refer to this process to check the IIS security settings for the "Default web site .)
Another way to solve this problem is to change the Web access mode from FrontPage to file share ).
Change the Web access mode to File Share)

In Solution Explorer, right-click the project name and select "properties" from the shortcut menu ".
In the In the properties page dialog box, open the "general properties" folder and select "Web Settings ".
Under "Web server connection", click "Web Access Mode" and select "file sharing" from the list box ".
Click OK to close Property page dialog box.
Manually attach
If you follow these troubleshooting steps and still receive an error message when you start debugging, you may need to manually attach it to debug the application.

Manually attach

Start the application without debugging. (Select "start execution (not debugging)" from the "debug" menu )".)
Attach to the appropriate IIS process or auxiliary process. By default, the ATL server application is inetinfo.exe, And the ASP. NET application is aspnet_wp.exe. Use the following process to determine the process in which the ASP. Net or ATL server application runs.
Check under which process the ASP. NET application runs

Use Visual Studio. NET or another text editor to open the machine. config file of the application.
Find the following process model attributes:
Enable
If enable is set to true, the application runs under aspnet_wp.exe (this is also the default setting .)

If enable is set to false, the application runs under inetinfo.exe.

Check the process in which the ATL server application runs

In Solution Explorer, right-click the project name and select "properties" from the shortcut menu ".
In the In the properties page dialog box, open the Web deployment folder and select general ".
View the "Application protection" settings.
If this parameter is set to "low (IIS Process)", the application runs under inetinfo.exe.
If this is set to "medium (pool)", the application runs under the dllhost.exe process (same as other ATL server applications in the pool ).
If this parameter is set to "high (independent)", the application runs under the dllhost.exe process (different from other ATL server applications ).
Click OK to close Property page dialog box.
See debugging scripts and Web: errors and troubleshooting