I found this issue too upon updating to the latest patch. It is definitely a patch-induced issue rather than anything to do with CC or whatnot. I found an additional issue when i went to correct the disguise in cas.fulleditmode whereby all the body options (nose, eyes, ears etc.) were for humans when I went to edit either form! I could no longer access alien eyes, skin colours, or anything else. The only solution I found was to create an Alien freshly from scratch to replace the 'broken' sim. Luckily I hadn't been playing this particular file for very long, so this wasn't much of a problem, other than the effort of replicating the sim by hand (seriously why isn't there a "clone sim"/"duplicate sim" option in cas.fulleditmode?? That would've saved a lot of time...) I haven't taken any of my sims into CAS since doing this - and I actually moved the family to the clipboard whilst replacing my Alien too, so I don't know if that had an effect. I think this might only effect pre-existing Alien sims, but I'm not keen on testing it and 'breaking' my new Alien... I guess I will find out for sure when he ages up.