instead of theme=tree it should be theme="tree" (with quotes)
also folder structure should be like below,
sd:/crazyintro
sd:/crazyintro/crazyintro.xml
sd:/crazyintro/tree/
sd:/crazyintro/tree/(All the theme files...)
Other troubleshooting hints
1. Open crazyintro.xml in internet explorer or another xml validating tool so that it's valid.
2. The width and height of the images you use in your theme should be divisible by four.
3. Ensure that jpegs / pngs do not contain unsupported metadata.