Yes, the V4.2 character is available in your library, but the question is the same:- 

Are you sure you are trying to install the Creature Morphs into the same Runtime where your V4.2 character and morphs are installed? If you are not, then you will get that message, since the product installer cannot find the V4.2 files. When that message appears, the window has a title that says something like "Dependency Error".

If you are sure you are selecting the parent folder of the Runtime where your V4.2 character is installed, then I do not know why this message is coming up. Sorry!

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)