trainCasca​deObjectDe​tector Matlab error

I am working on matlab to do object detection in images.

I have used the LabelImage toolbox to generate the positive images. The negative images are generated as crops from the rest of each image. When I run the code below I have this error.

load('positives.mat');
trainCascadeObjectDetector('trainingHaar.xml',positives, 'Negatives/', ...
                           'NumCascadeStages', 5, 'FeatureType', 'Haar');

Error reading instance 101 from image 2, bounding box possibly out of image bounds.