I finally got it working.
But now I have a new problem...
When I run the program I get:
Unhandled exception at 0x5AB12382 (sfml-graphics-d-2.dll) in Client.exe: 0xC0000094: Integer division by zero.
I don't know for sure if the texture is loaded proberly on the sprite because the error happens at
Window.draw(Sprite);
So can you check if a sprite or texture is valid before you draw? I haven't seen that because everything looks a void...
Edit: found this "It is important to note that the sf::Sprite instance doesn't copy the texture that it uses, it only keeps a reference to it. Thus, a sf::Texture must not be destroyed while it is used by a sf::Sprite (i.e. never write a function that uses a local sf::Texture instance for creating a sprite).". I will test it without the function...