Train Animal Companion

[domare]

I started out with a "Young Wolf" as a AC.  Then, I used the train AC tool on a Cave Prowler, which worked fine (although by mistake).  With DM assistance, I attempted to change from Prowler back to Young Wolf, but received an error message indicating the animal was not on the list of trainable animals.  We even tried other animals such as Bear Cubs, without any luck.  Anyone know how my character could get the Young Wolf back as an AC?

[Talir]

Only through DM help. As far as I know there's no Young Wolf spawns in the Underdark so I am not sure what the bug is? You changed your animal companion into something else.

[the gardener]

Kind of linked I imagine, so posting here. I tried to train a new animal companion today, all the messages indicated success and 200xp was taken.

However on trying to summon for the first time I got the message "you have no trained animal companion".