Missing Characters

Wonder if someone can help regarding characters in Articulate. I am updating a training package I created a few years ago and I am using the following characters:

• Brian
• Nicky
• Ron
• Atsumi

I have tried to change the pose of the character but I get the error ‘This character isn’t installed and its pose can’t be changed. Subscribe to Articulate 360 for all access to all ’. I have tried to insert a character and only Atsumi is in the list. The rest are missing?

I have Articulate Storyline 3 installed but the training package was created in Articulate Storyline 2. Would I have had a character pack installed in Articulate Storyline 2 but it hasn’t been installed in Articulate Storyline 3? Is why I get the error?

Any help appreciated.

Thanks
John