Why don't my fish eye lens work?

I was able to take a picture outside but not inside, the picture is completely dark, doesn't matter what setting, it's all dark unless I'm outside. -Nikon D3000

Set it on auto. You may need to set the ISO on auto too.
What did the EXIF for the dark exposure say really?

The exposure is too short for the prevailing light intensity inside. Use Auto as suggested or use a long shutter speed. 1/2sec at f4 and ISO 100 is a rough guide for a room with a light on & without the light in the field of view.

Photography 101 - it's an exposure issue.