This should be fixed in a second.

Is this now fixed or is it still happening?

Just pushed a fix for this, let me know if it doesn't work :)

This is from the battle board: If you just adopted your pet, there is a 30 day waiting period before you can battle with it. That's a preventive measure to keep people from lending out pets for events.Unfortunately, if there's a plot going on, that means your pet is probably going to have to sit this one out.

So yes you will have to wait 30 days before you can battle!

Locking as the original errors are gone and you can battle!