I recently purchased TK2D with hopes of using it in my current project, but the TK2D options aren't showing up (such as adding a camera using Create > TK2D > Camera; the entire TK2D selection doesn't appear). The folders were added to my project correctly. When I start a new project and select the option to use TK2D all the options appear correctly. Is it possible to use TK2D in existing projects, or can it only be used in new ones?