The engine is translating thousands of graphics files into a format your specific graphics card (GPU) can understand.
If the freezing occurs at a different percentage, such as 50% during packaging or 73% while loading, the specific cause may differ. You will likely need to explore the Output Log for specific errors that can guide you further. However, for the standard load screen freeze at 45%, the solutions listed above should get you back on track. Start with the simplest fix (installing Unreal Engine 4 and waiting for shaders), and you will likely be creating your own mods in no time. hello neighbor mod kit stuck at 45