Error while trying to run project: Unable to start debugging on the web server. The project is not configured to be debugged.

For those of you who have received this error message with Visual Studio and IIS, hopefully this will save you some time...

I recently was reorganizing some of my applications on my computer as my company is about to begin developing a new version of our e-commerce ticketing software. In restructuring, I was going to name my virtual directories according to my namespace in the application (e.g. "Ecommerce.Application"). Then, underneath the parent directory, i would make new virtual directories for each version of the application (see image below; click for larger image)



I didn't even think twice about putting the dots (".") in the name of my virtual directories, because I have done it many times before with no problems. However, this time, when I set up the virtual directories as I did above, and then tried to build and debug the application, I got the following error: Error while trying to run project: Unable to start debugging on the web server. The project is not configured to be debugged.



I made sure my "debug" attribute of the "compilation" tag in my web.config was set to "true". I made sure that the "ASP.NET debugging" option was selected in the project properties. I tried every other suggestion I found online. Finally, after about four hours of frustratingly searching the internet and trying anything to make it work, I finally realized that I had never used dots (".") in the virtual directory name when the application was running more than one virtual directory deep.

Sure enough, when I changed the name of the parent virtual directory to not include any dots (see image below; click for larger image), the problem went away.



As far as I know, this hasnt been mentioned anywhere else online and it seems like a bug with Visual Studio to me. (I am using .NET 1.1.4322 and VS.NET 2003).

Hopefully this will help others with the same problem and maybe MS can figure out what the problem is in the debugger that wont allow this and fix it in future versions.

--Jorin