I have installed VS 2015 RTM (nothing else) and I\'m unable to debug any solution, not matter if it\'s an existing one or a brand new one (created with VS 2015 and compiled
I hade the same problem. After trying the other solutions here without luck, I had to repair the installation through the installer.
Control Panel > Programs > Programs and Features
Then scroll down to Microsoft Visual Studio, right click it, then "Change". Then at the bottom of the window, click Repair. The repair process will take a decent amount of time, and at the end you will have to restart your computer.
This fixed the problem to me, and I hopes it will help you.