"Unable to start debugging" message in VS 2008

Question

I have this message when I start debug in VS 2008:

Error while trying to run project: Unable to start debugging

Because of this I cannot debug any programs any more. Any ideas what causes this?

Answer 1

Sometimes it means the URL you have setup for the project in the Project Properties doesn't match what it is in IIS.

Answer 2

Assuming a client app and not a web app, there are a few things to try:

1. Make sure you run Visual Studio as an admin (elevated).
2. Make sure you have cleanly built your project and have matching symbols (.pdb and .exe have same timestamp).
3. Make sure you are not already debugging the app with VS or a different debugger.

Answer 3

This is also possible when in VS->Server Explorer Application debugging is enabled or CLR/SQL debugging is enabled..

Disabling that might solve the issue..

Answer 4

Verify that you are a member of the Administrators group and the Debugger Users group on the computer.

Answer 5

I had this problem when I brought my code over from another machine. I kept getting that message when trying to debug until I completely cleaned out the output directory (I just manually deleted everything in it). Once I did that, I could run in debug mode.