[SharePoint 2010 - Developement - Debuging] Error while debugging (Erreur au debuguage de Visual studio)

While debuging i got that tricky message :

“The source file is different from when the module was built. Would you like the debugger to use i…”

French :

“Le fichier source est différent de celui utilisé lors de la génération du module. Souhaiter_vous tout de même que le débogueur utilise ce fichier”

I’m programming a Sharepoint 2010 SOlution with visual studio and I have a project name Common where i put all my classes.
I was in debuging mode in order to see what’s wrong with my code. Actually i was using a dll from that common project in the package of the SharePoint project. This dll was the dll in the release folder. But my project was build in the debug mode…
All i had to do was to choose the right dll (from the debug project). Or to build the project in the Release mode.
Hope that help