Sims 3 - Toddler Trouble!?

I am currently a fan of Sims 3 and i own a fully legit licensed copy i got for christmas, However my sim, named, Alice is the mother of 3 kids, two birth toddlers and an adopted child, all male. Markus, the youngest had became glitched, i cannot see him, he is in his cot but all i can see is the thought bubbles and a dot that is his shadow, the other kids are alright but Markus is glitched, how can i make him normal again, and not glitched? Help, please!