Why can't my characters turn?

If they cannot turn, you probably forgot to add turning motions in your locomotion, or forgot to add mirrored motion clips for each turning motions

Locomotion Model including only turn left motions	Locomotion Model with mirrored motions

For example if your set of motions include only turn left motions, you should activate the mirror motion on them, click the  yellow hemisphere icon so that it becomes a yellow ball.

You should also check that there is no warning in the script editor about missing mirror mapping in your character file, otherwise the mirrored motions will be ignored.