Today, when I open my old project there was this error “No exports were found that match the constraint”, I then search google for this problem and the solution is fairly simple.
This error happen when I installed new unity 5.2.1f, the installer installed visual studio 2015, the problem is solved by clearing Visual Studio Component Model Cache.
Just type %AppData% in run box ( win button + R ) , it will take you to your AppData/Roaming folder, just go up once and you will find 3 folder .. Local, LocalLow, and Roaming.
The exact folder is
Visual Studio 2012
C:\Users\<Your User Name>\AppData\Local\Microsoft\VisualStudio\11.0\ComponentModelCache
Visual Studio 2013
C:\Users\<Your User Name>\AppData\Local\Microsoft\VisualStudio\12.0\ComponentModelCache
Visual Studio 2015
C:\Users\<Your User Name>\AppData\Local\Microsoft\VisualStudio\14.0\ComponentModelCache
Just find the folder and rename or delete, then run the visual studio again and open the project, then all problem solved.