I have a script that uses GetVisemeKeys() and that ran fine in API 072. Have in API 073, I get an error.

Here is a snippet to illustrate this (before running, make sure there is at least one avatar is in the scene):

import RLPy

avatar_list = RLPy.RScene.GetAvatars()
avatar = avatar_list[0]
viseme_animator = avatar.GetVisemeComponent()

audio_object = RLPy.RAudio.CreateAudioObject()
audio_object.Load("C:\\Sample.wav") # replace with existing .wav file
clip_name = "VisemeClip"
clip_start_time = RLPy.RTime(0)
viseme_animator.LoadVocal(audio_object, clip_start_time, clip_name)

# get all viseme keys
print("get all viseme keys")
keys = viseme_animator.GetVisemeKeys()

At this point the script fails with an error:
<class 'AttributeError'>, File: C:\Program Files\Reallusion\Python_API_073\Bin64\RLPy.py, Line: 80