EEF,

Are you on .22b ? I have had all the issues you mention on previous versions but not the latest. I have not had Muvizu crash on me for a couple of months and I really, really push it. The missing characters used to happen in 0.20b (not sure about .21b) so any sets saved from previous versions in that state will be a problem. If you choose view>set window and look at the characters you will probably find the character is still there, just in a parallel black universe that he can never escape. You may be able to select him, cntl-C, select something else to get back to the real world then cntrl-V to get him back - not sure if this will work though.

Ziggy is right. At some point you will have to engage with Sketchup in order to progress your Muvi making. I resigned myself to this in the spring and now have a few basic skills, creating shapes and adding textures as well as amending existing models for my needs. As Zig says, 50% don't work and you will spend an age making sets, but if you want to move ahead then Sketchup is your man.