Silverlight 5.0 debugging issue on Windows 10

Do you have a 64 bit OS ? If so - uninstall Silverlight (developer!) and make sure you install the silverlight.exe (developer!) not the 64 bit version. That worked for me. HTH

Go to the properties of the Web folder start project. Click Web on the left tab. Unclick Silverlight in the debuggers.

Not a total solution but at least it allows you to debug other portions.

I had this issue and Uninstalling and Reinstalling didn't work.

Error in debug mode (F5 Debug solution configuration) was "Unable to start debugging. The Silverlight Developer Runtime is not installed"

In Debug configuration I would get the above error but finally I put the solution into release mode and it worked - then back to debug mode and everything worked without error.

Seems like a really odd fix but sure enough closing and re-opening the solution everything works now - Same install procedure as OP.

Another thing that's interesting is, the Debug only works in Chrome. If I target IE or edge I still get "Unable to start debugging. The Silverlight Developer Runtime is not installed"