Dreamweaver UltraDev plugin on my computer encountered an error

Hi,
While installing the Dreamweaver UltraDev plugin on my computer I encountered an error “Selected Class not found”. Any ideas?

Dreamweaver UltraDev
Selected Class not found. Please verify that:
1. The specified class file in your class or in the UltraDev classes folder.
2. The class file is in a directory structure that matches the class package.
