So, when I was trying to make an GUI System for the game I'm making when I tried to test it the window shows up but was frozen and only white, then after a few seconds I will suddenly get a pop up window saying "Game.exe has stopped working" then it crashes. I don't know what I'm doing wrong, what could have possibly caused this? (I will post code if needed)

I found it, it was in the main() function.

int main()
{ 
    std::cout << "Program begins...\n";
    std::string title = "Total War";
    std::cout << "Program begins...2\n";
    App* Main_Window = new App(title);
    std::cout << "Program begins...3\n";
    Gui::FontLoader fontLoader;
    std::cout << "Program begins...4\n";
    fontLoader.loadFont("FREESCPT.TTF");
    std::cout << "Program begins...5\n";
....

When I start the program the "Program begins...5" doesn't get printed, so I commented the "fontLoader.loadFont" function then my program worked without crashing, but I don't know why this happened, that line wasn't causing issues before, and I also haven't changed anything in that part of the code, but here's the code for that:

// header file
namespace Gui
{
    class FontLoader
    {
        public:
            sf::Font* font;

            FontLoader();
            bool loadFont(sf::String filepath);
    };
...
// .cpp file
Gui::FontLoader::FontLoader() {}

bool Gui::FontLoader::loadFont(sf::String filepath)
{
    if (!font->loadFromFile("Art/Fonts/" + filepath))
    {
        return false;
    }
    return true;
}

I haven't changed anything recently on that class/code, the only time that problem started to happen is when I made changes to my GUI system...

The most likely problem is that you aren't initialising the font member of the FontLoader class, and as it is a pointer to a sf::Font object it is most likely pointing to an invalid address when you call loadFont. The solution is to replace 'sf::Font*' with 'sf::Font' and the '->' with a '.', which will mean that the font member is always initialised when you construct a FontLoader.

The most likely problem is that you aren't initialising the font member of the FontLoader class, and as it is a pointer to a sf::Font object it is most likely pointing to an invalid address when you call loadFont. The solution is to replace 'sf::Font*' with 'sf::Font' and the '->' with a '.', which will mean that the font member is always initialised when you construct a FontLoader.

Thanks dude, I changed those and now it works without crashing :D