Gosh I feel stupid. Thank you, that was it. They were set to Solid. Now the player walks freely through them. Thank you very much!
C2 is an amazing engine. I've tried so many: Unreal Engine 4, Unity (several versions), C#, C++, Gamemaker Studio, Cocos2d, Xamarin, AGK2, Leadwerks, Clickteam Fusion 2.5, Stencyl, Delphi, C++ Builder, Alice, Allegro, Corona, DarkBasic, FPS Creator, Game Builder Studio, Game Salad, GameStudio, GLBasic, Juice (sound engine), Lazarus (Pascal), Monogame, XNA, Ogre3D, Phaser, PureBasic, Qt, RPGMaker, SDL, SFML, and SharpDX. Construct 2 is the only environment that has amazed me! It's taken me several years of course to try these engines, but none has been so easy and at the same time so full of features as C2.