When I look at the class declaration, all the functions are underlined, even the constructor. The compiler is complaining that it cannot locate the function definitions.
I am using SMFL 2.3.2 I have included the lib folder and the include folder.
Now I admit that I am somewhat new to programming, but I was able to set up the HGE engine and do a little programming with it. Never had any issue and the setup process is very similar.