You should use the code=cpp tag to post code and provide information about your OS, compiler, toolchain, SFML version, graphics card and driver version, etc. etc. (see
here).
As for the problem you might want to search the forum a bit, there have been quite a few similar threads.
Maybe an update to the latest SFML commit will already fix it.
Looking at your code I'm asking myself whether you've been working a lot with C or Java, because you don't need to make very thing a pointer, especially not raw pointers. Thus you should never use pointers if it's not nessecary, make sure if you couldn't use a reference instead and probably in all cases use smart pointers instead of raw pointers (see
here for more details).
Besides that you shouldn't use global variables and especially not global SFML resources (i.e. sf::Font).