What's wrong when train on my own dataset?

[CloverKids]

Traceback (most recent call last):
File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1334, in _do_call
return fn(*args)
File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1319, in _run_fn
options, feed_dict, fetch_list, target_list, run_metadata)
File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1407, in _call_tf_sessionrun
run_metadata)
tensorflow.python.framework.errors_impl.UnknownError: IndexError: index 21 is out of bounds for axis 1 with size 13
Traceback (most recent call last):

File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\ops\script_ops.py", line 207, in call
ret = func(*args)

File "C:\Users\Administrator\Desktop\YOLOv3_TensorFlow\utils\data_utils.py", line 214, in get_batch_data
img_idx, img, y_true_13, y_true_26, y_true_52 = parse_data(line, class_num, img_size, anchors, mode, letterbox_resize)

File "C:\Users\Administrator\Desktop\YOLOv3_TensorFlow\utils\data_utils.py", line 174, in parse_data
y_true_13, y_true_26, y_true_52 = process_box(boxes, labels, img_size, class_num, anchors)

File "C:\Users\Administrator\Desktop\YOLOv3_TensorFlow\utils\data_utils.py", line 109, in process_box
y_true[feature_map_group][y, x, k, :2] = box_centers[i]

IndexError: index 21 is out of bounds for axis 1 with size 13

 [[{{node PyFunc}}]]
 [[{{node IteratorGetNext}}]]

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:/Users/Administrator/Desktop/YOLOv3_TensorFlow/train.py", line 140, in
feed_dict={is_training: True})
File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 929, in run
run_metadata_ptr)
File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1152, in _run
feed_dict_tensor, options, run_metadata)
File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1328, in _do_run
run_metadata)
File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\client\session.py", line 1348, in _do_call
raise type(e)(node_def, op, message)
tensorflow.python.framework.errors_impl.UnknownError: IndexError: index 21 is out of bounds for axis 1 with size 13
Traceback (most recent call last):

File "D:\Program_Files\Anaconda3\envs\tensorflow\lib\site-packages\tensorflow\python\ops\script_ops.py", line 207, in call
ret = func(*args)

File "C:\Users\Administrator\Desktop\YOLOv3_TensorFlow\utils\data_utils.py", line 214, in get_batch_data
img_idx, img, y_true_13, y_true_26, y_true_52 = parse_data(line, class_num, img_size, anchors, mode, letterbox_resize)

File "C:\Users\Administrator\Desktop\YOLOv3_TensorFlow\utils\data_utils.py", line 174, in parse_data
y_true_13, y_true_26, y_true_52 = process_box(boxes, labels, img_size, class_num, anchors)

File "C:\Users\Administrator\Desktop\YOLOv3_TensorFlow\utils\data_utils.py", line 109, in process_box
y_true[feature_map_group][y, x, k, :2] = box_centers[i]

IndexError: index 21 is out of bounds for axis 1 with size 13

 [[{{node PyFunc}}]]
 [[node IteratorGetNext (defined at C:/Users/Administrator/Desktop/YOLOv3_TensorFlow/train.py:60) ]]