loss error

[five1wheel]

Traceback (most recent call last):
File "train.py", line 694, in
main(args)
File "/mnt/e/test/ContextPose-PyTorch-release-master/mvn/models/loss.py", line 93, in forward
keypoints_3d_pred = torch.tensor(keypoints_3d_pred, dtype=torch.float)
ValueError: expected sequence of length 8 at dim 1 (got 7)
May I ask why the following brother reported the error?