I'm having an issue in my game where after throwing a birthday party for my toddlers, they just don't grow up. Babies, children, teens, etc. grow up, but not toddlers. If I have them for less than a day, I can grow them up at the cost of not choosing their traits, but once I've had a toddler for awhile, they can't grow up. If I set the aging on and their birthday goes and passes, they become unselectable.

If anything else, my toddlers are plantsims, which I don't know if it adds to the problem.

EDIT: I can age the babies up to toddler with testingcheats, but it seems I can't trigger the aging so they become children. The camera just zooms in on them and the action appears but it cancels itself. If I move out of the lot, they disappear and I can't move back into that same lot. I also can't edit them in CAS as it locks up on the loading screen.

Any help would be appreciated~

Type in 'Testingcheatsenabled true' in the cheatbox, right click your toddler and press 'trigger age...' To choose their traits , right click after they've aged and press 'change traits' or something like that.

I've tried that, it doesn't work. The action cancels itself out.

I've found that messing with enable ageing can have odd effects. Using mc to move your toddler to a different household might work.
Then try the age transition.

I've had aging off and never messed with it. And I can't move the toddler to a different household, they'll disappear (and master controller is rather difficult to work with).

Another Edit: I tried a factory reset on the game, the toddlers in a specific save file just won't age no matter what. I think every other toddler in different family saves age, just not this one.

EDIT: I believe I've found the issue was a possible conflict with B-flysims3 child/toddler hair (despite Custard telling me there's nothing wrong with the files; weird). Was able to remove it and now my toddlers can age again (but me thinks there was possible corruption in that save due to my other child randomly deleting itself and Error Trap going wonky, so it had to go. At least this issue won't happen again in future saves).