3D calibration opencv error

Has anyone encountered a problem trying to get the 3d matrices of each camera? I’ve been through the example DLC notebooks and have removed all of the images without corners/pairs but I’m still not having any luck figuring out why I’m getting this error. Any ideas? thank you!

deeplabcut.calibrate_cameras(config3d, cbrow =9,cbcol =7,calibrate=True,
…: alpha=0.9)
Saving intrinsic camera calibration matrices for cam-01 as a pickle file in /home/kenzie/Documents/DeepLabCut/leventhal-lab/leventhal3D-Kenzie-2019-09-12-3d/camera_matrix
Mean re-projection error for cam-01 images: 0.052 pixels
Saving intrinsic camera calibration matrices for cam-02 as a pickle file in /home/kenzie/Documents/DeepLabCut/leventhal-lab/leventhal3D-Kenzie-2019-09-12-3d/camera_matrix
Mean re-projection error for cam-02 images: 0.060 pixels
Computing stereo calibration for

error Traceback (most recent call last)
----> 1 deeplabcut.calibrate_cameras(config3d, cbrow =9,cbcol =7,calibrate=True,alpha=0.9)

~/.conda/envs/dlc-ubuntu-GPU/lib/python3.6/site-packages/deeplabcut/pose_estimation_3d/camera_calibration.py in calibrate_cameras(config, cbrow, cbcol, calibrate, alpha)
156 for pair in camera_pair:
157 print("Computing stereo calibration for " %pair)
–> 158 retval, cameraMatrix1, distCoeffs1, cameraMatrix2, distCoeffs2, R, T, E, F = cv2.stereoCalibrate(objpoints[pair[0]],imgpoints[pair[0]],imgpoints[pair[1]],dist_pickle[pair[0]][‘mtx’],dist_pickle[pair[0]][‘dist’], dist_pickle[pair[1]][‘mtx’], dist_pickle[pair[1]][‘dist’],(h, w),flags = cv2.CALIB_FIX_INTRINSIC)
160 # Stereo Rectification

error: OpenCV(4.1.1) /io/opencv/modules/calib3d/src/calibration.cpp:3332: error: (-215:Assertion failed) nimages > 0 && nimages == (int)imagePoints1.total() && (!imgPtMat2 || nimages == (int)imagePoints2.total()) in function ‘collectCalibrationData’

maybe related: https://github.com/bvnayak/stereo_calibration/issues/4