Getting error in yolo_non_max_suppression function

---------------------------------------------------------------------------
*InvalidArgumentError                      Traceback (most recent call last)*
*<ipython-input-12-11f8efabc036> in <module>*
*      8 print(f"iou:    \t{iou(boxes[0], boxes[1])}")*
*      9 *
*---> 10 scores2, boxes2, classes2 = yolo_non_max_suppression(scores, boxes, classes, iou_threshold = 0.9)*
*     11 *
*     12 assert np.allclose(scores2.numpy(), [0.855, 0.828]), f"Wrong value on scores {scores2.numpy()}"*

*<ipython-input-11-cff628b38fb4> in yolo_non_max_suppression(scores, boxes, classes, max_boxes, iou_threshold)*
*     51             # Append the resulting boxes into the partial result*
*     52             # Use tf.gather() with 'selected_indices' and `nms_indices_label`*
*---> 53             nms_indices.append(tf.gather(selected_indices,nms_indices_label,validate_indices=selected_indices, axis=None, batch_dims=0, name=None))*
*     54 *
*     55     # Flatten the list of indices and concatenate*

*/opt/conda/lib/python3.7/site-packages/tensorflow/python/util/dispatch.py in wrapper(*args, **kwargs)*
*    199     """Call target, and fall back on dispatchers if there is a TypeError."""*
*    200     try:*
*--> 201       return target(*args, **kwargs)*
*    202     except (TypeError, ValueError):*
*    203       # Note: convert_to_eager_tensor currently raises a ValueError, not a*

*/opt/conda/lib/python3.7/site-packages/tensorflow/python/ops/array_ops.py in gather_v2(params, indices, validate_indices, axis, batch_dims, name)*
*   4693       name=name,*
*   4694       axis=axis,*
*-> 4695       batch_dims=batch_dims)*
*   4696 *
*   4697 *

*/opt/conda/lib/python3.7/site-packages/tensorflow/python/util/dispatch.py in wrapper(*args, **kwargs)*
*    199     """Call target, and fall back on dispatchers if there is a TypeError."""*
*    200     try:*
*--> 201       return target(*args, **kwargs)*
*    202     except (TypeError, ValueError):*
*    203       # Note: convert_to_eager_tensor currently raises a ValueError, not a*

*/opt/conda/lib/python3.7/site-packages/tensorflow/python/ops/array_ops.py in gather(***failed resolving arguments***)*
*   4676     return params.sparse_read(indices, name=name)*
*   4677   except AttributeError:*
*-> 4678     return gen_array_ops.gather_v2(params, indices, axis, name=name)*
*   4679 *
*   4680 *

*/opt/conda/lib/python3.7/site-packages/tensorflow/python/ops/gen_array_ops.py in gather_v2(params, indices, axis, batch_dims, name)*
*   3843       return _result*
*   3844     except _core._NotOkStatusException as e:*
*-> 3845       _ops.raise_from_not_ok_status(e, name)*
*   3846     except _core._FallbackException:*
*   3847       pass*

*/opt/conda/lib/python3.7/site-packages/tensorflow/python/framework/ops.py in raise_from_not_ok_status(e, name)*
*   6841   message = e.message + (" name: " + name if name is not None else "")*
*   6842   # pylint: disable=protected-access*
*-> 6843   six.raise_from(core._status_to_exception(e.code, message), None)*
*   6844   # pylint: enable=protected-access*
*   6845 *

*/opt/conda/lib/python3.7/site-packages/six.py in raise_from(value, from_value)*

***InvalidArgumentError: indices[1] = 1 is not in [0, 1) [Op:GatherV2]***

I am getting this error. Can I get a mentor to help me solve this? I do not have much idea, on solving it. Please suggest a mentor or looking forward to a mentor.