Spam.plotting.orientationPlotter.plotSphericalHistogram

Question 1: Based on OSX system, and installing spam into Anaconda with package on conda-forge, when trying totally the same Orientations toolkit examples (Spam.plotting.orientationPlotter.plotSphericalHistogram) on the website-https://ttk.gricad-pages.univ-grenoble-alpes.fr/spam/spam_examples/orientations, an error "verts must be a list of (N,3) array-like " will appear. Question 2: There are so so many (1,0,0) vectors with small "intervoxel position for PCA" values(0 or 1 or 3 or 4...) in contact orientation list calculated by 'RW', I don't know if this phenomenon is normal or not, maybe the segmentation or contactinglabelRefined is not good...