I can't drag one specific object from illustrator to animate, other objects drag across fine

I'm not sure if this is an animate issue or illustrator issue but basically, a while ago I drew a train in illustrator, and yesterday I made some adjustments (changed the doors). The train that I originally drew I can copy across to animate n problem, but the copy of it that I made the changes to doesn't. When I try to copy it over it says its copied it over but nothing is actually there. If I copy it across with the new doors then only the doors actually copy across. If I release the live paint on the train then I can get it to copy across. Why is this happening and how do I fix it, I don't want to remake the train. (I have tried closing and opening illustrator and animate and have restarted my computer)