Unity unresponsive on scene change

I am making a 2d tower defense game, and I am trying to load the main scene from a different one in the editors play mode and when its built. Currently when I try to load the scene Unity stops responding. How do I fix this?

This depens on how BIG your scene is and the target hardware. But I’m assuming you’re just using SceneManagement.LoadScene which indeed will stop all process and try to load the next scene.

You can use SceneManagement.LoadSceneAsync so the loading run Asynchronously (it loads your next scene in the background, though it will still lags a little bit depending on the scene and target hardware). You would have to put Loading Screen UI to make it pretty and prevent any inputs until the next scene is loaded.