Masking problems- can someone help?

Question

I'm trying to create a mask by copying and pasting an image I made in Illustrator. The times this has worked seemed erratic and random. Most of the time the image comes over and the mask is applied, but nothing is masked out. I took a screenshot of what's going on.
http://i225.photobucket.com/albums/dd106/scorpio_vs/masking.jpg
The mask of the jellyfish is on, but the solid hasn't been masked out. It's just on top of the solid... I'm not sure why this is happening.
Can anyone help me?

Answer 1

First:
Why are you doing this, rather than using the Create Shape Shapes From Vector layer feature? With that, you can import an Illustrator file and convert it to vector graphics shape layers in After Effects. This is almost always much better than using masks on solids, which is the old way from before we had vector graphics shape layers.
Second:
Don't just paste onto the solid like that. Copy the shape in Illustrator. Create a mask on the solid with the Pen tool in After Effects; just clicking once to draw a single point is adequate. With the mask path property selected (it should actually already be selected because you just created it), paste. This puts the path from the Illustrator layer into the right place with the right properties already set.