[YOLOv8] IndexError: index 1 is out of bounds for dimension 1 with size 1

Starting training for 1 epochs…

  Epoch    GPU_mem   box_loss   cls_loss   dfl_loss  Instances       Size

0%| | 0/27 [00:03<?, ?it/s]

bbox_scores[mask_gt] = pd_scores[ind[0], :, ind[1]][mask_gt] # b, max_num_obj, h*w
IndexError: index 1 is out of bounds for dimension 1 with size 1

I placed yaml path settings, images, and label folders well, but I don’t know why that error phrase pops up.