Debugging is not working in VS 2008 Project

You may have accidentally changed your Web Site configuration from Debug to Release. Change it back and debugging should start work again.

- Click Build and select Build in Configuration Manager value
- Change the Active solution configuration from Release to Debug and click Close.
- Try debugging and see if your breakpoints are hit.

Hope this helps.

Unable to start debugging. The silverlight managed debugging package isn't installed.

Suppose you installed latest version of Silverlight (Silverlight 4), It may break the your current silverlight development environment with VS 2008. After in the Silverlight 4 installation, if you try to debug any Silverlight 3 project, you will get a message from Visual Studio 2008, saying "Unable to start debugging. The Silverlight managed debugging package isn’t installed"..

Solution :

To fix this error, install the Silverlight Developer Run time. You can get it from here : http://go.microsoft.com/fwlink/?LinkID=188039.

Installation failed with error code: (0x80070643), Fatal error during installation for VS 2008

While I was installing Silverlight. I got following error.

Problem:

Exe (d:\d7baf3d2979ba5016553d37455c7664c\PurgeSLTCache.exe) succeeded.
Exe (C:\DOCUME~1\JAIPRA~2.SIL\LOCALS~1\Temp\Silverlight Tools RTW\Silverlight.2.0_Developer.exe) failed with 0x80070643 - Fatal error during installation. .
Exe (d:\d7baf3d2979ba5016553d37455c7664c\PurgeSLTCache.exe) succeeded.
Final Result: Installation failed with error code: (0x80070643), Fatal error during installation.

Solution :

1- After installing VS 2008 SP1 restart your system.
2- Remove all the previous version of Silverlight.
3- Run setup again

It will work.