Hello! I recently bought this plugin, and testing it I found 2 errors:
1.- When I save the game and load it, I get an error screen if I talk with a character that uses this plugin portrait animation for the messages. I tested this with my game and the demo project you provided. Both of them give this error.
This screenshot is from your demo project: 
And this one is from my game: 
The error text is pretty similar.
2.- When I use the "show DB alone" option in your demo project, save the game, and load it, the DB animation doesn't appear anymore. Neither on the screen nor in the messages when I talk with the character.