Characters not displaying

I'm fairly new to using Storyline and I've been creating a Story using characters throughout.  Last time I was working on this particular project, when I clicked insert>character> photographic character, about 12 different characters were available to choose from and I could then select different poses.  Now when I access this section and the window opens up, I click on the 'character' tab to choose which person I want to use and only a big head shot of the Atsumi character appears, I can't see any of the other ones I previously was able to access.  Any ideas on how I can get them all back as I need to change a pose for one of the characters and even when I access the character in the slide and right click then select 'change character' it still just opens up to the head shot of Atsumi (also with her different poses available).

Thanks!