Hello everybody !
This is my first time wth QT and Visual studio and it's not easy for me :/
I want to open an existing project, it was developped with Visual Studio and using QT, so I installed QT 5.6 and the plugin QT for Visual studio 2015.
But when I want to compile I have an error :
There's no QT version assigned to this project for platform x64. PLease use the 'change QT version' feature and choose a valide Qt version for this platform.

So I clicked on :
QT5>QT Options> Qt Versions : Name 5.6 path C:\Qt\5.6\msvc2015_64
And it's the Default Qt\Win version.
I saw on another thread that you can change the QT settings in QT5>QT Project Settings, but this option is gray for me and i can't click on it.
How can i fix this problem ?
Thanks you very much.
Best regards,
Psykomusic