Hello Neighbor Mod Kit Stuck At 45 ((new)) Link
The Mod Kit is built on Unreal Engine 4 (UE4). When you launch it for the first time, or after an update, the engine must compile thousands of shaders. Unreal Engine
If you're still stuck, consider reporting the issue on forums or comment sections of the mod's page. Provide details like: hello neighbor mod kit stuck at 45
In the Unreal Engine architecture (which powers the Mod Kit), is the specific stage where the editor begins compiling shaders and initializing global project settings. The Mod Kit is built on Unreal Engine 4 (UE4)