Problem with selection

Hi,

I've got a problem with Unity Editor. I can't select an object just by clicking it, I'm forced to select with a selection square (Hold Mouse-LeftClick and enclose the object I'm interested). That's a little unconvenient when I have a big object and I'm forced to unzoom or if I have two objets really close together and I don't want to select both of them. I've got the problem on all scenes but not on other projects, so I guess I did a wrong manipulation who deactives the direct selection but I can't find anything about it in the documentation.

It was working fine until today, I tried uninstalling-reinstalling Unity with no results. I tried to restart Windows but no results either. So it has to be bound to my projects settings but I have no idea where to look. I'm on Unity 5.2.

Thanks in advance and have a nice evening.