Scene extremely dark when directional light shadows are enabled.

Everything in the scene is completely pitch black.

When the shadow distance is set to 100, everything near the camera is pitch black. And everything far away is bright. Changing the Ambient color affects the color of the shadows. How do I make the scene have normal shadows?

UPDATE:

When I turn the ambient color to bright. The scene is light, however, most of the objects are not receiving or casting any shadows. Here is a link to the image: https://drive.google.com/file/d/1VnqX8GNYX71T4AOLMUorUx6VZWWfIJQD/view?usp=sharing