Getting Error trying to append new face with 'a' option

[FelipeMiranda]

I get this error when face is recognized and I try to press 'a' to append new face

   press 'esc' to quit
  press 'a' to append a new face to the database
      (you'll be prompted for a name on the console)
  press 't' to retrain the model (if you appended faces there)
cam: ok.
cascade: cascades/haarcascade_frontalface_default.xml
image path empty /Users/felipe/VideoFaceRecognition/images
trained: 0 images 0 persons
Traceback (most recent call last):
  File "facerec_online.py", line 188, in <module>
    if (k == 97) and (roi!=None):
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()