Error when running colab demo: "This algorithm is patented and is excluded in this configuration"

[m0o0scar]

Hi. I'm trying to test the demo video on colab, but encounter the following error when running the "Run" step:

...

Filtered out frames []

************************
****  Compute flow  ****
************************
Sampled 522 frame pairs.
Resizing flow to (224, 384)
Loading pretrained model from 'checkpoints/flownet2.pth'.
Traceback (most recent call last):
  File "main.py", line 13, in <module>
    dp.process(params)
  File "/content/consistent_depth/process.py", line 117, in process
    return self.pipeline(params)
  File "/content/consistent_depth/process.py", line 71, in pipeline
    self.flow.compute_flow(frame_pairs, params.flow_checkpoint)
  File "/content/consistent_depth/flow.py", line 143, in compute_flow
    optical_flow_flownet2_homography.process(args)
  File "/content/consistent_depth/optical_flow_flownet2_homography.py", line 258, in process
    flow = infer(args, Flownet, device, im1, im2)
  File "/content/consistent_depth/optical_flow_flownet2_homography.py", line 179, in infer
    img1, img2, img2_reg, H_BA = getimage(img1_name, img2_name)
  File "/content/consistent_depth/optical_flow_flownet2_homography.py", line 151, in getimage
    (kpsA, featuresA) = detectAndDescribe(frame1)
  File "/content/consistent_depth/optical_flow_flownet2_homography.py", line 68, in detectAndDescribe
    descriptor = cv2.xfeatures2d.SURF_create()
cv2.error: OpenCV(4.2.0) /io/opencv_contrib/modules/xfeatures2d/src/surf.cpp:1029: error: (-213:The function/feature is not implemented) This algorithm is patented and is excluded in this configuration; Set OPENCV_ENABLE_NONFREE CMake option and rebuild the library in function 'create'

Done. Your results are saved at /content/consistent_depth/.
Video results are at /content/consistent_depth/results/ayush/R_hierarchical2_mc/videos/.
Disparity maps are at /content/consistent_depth/results/ayush/R_hierarchical2_mc/B0.1_R1.0_PL1-0_LR0.0004_BS4_Oadam/depth

Any idea what might be the problem and how to fix this? Thanks :)