Cv2 error can't read .pb file

[JayMwakideu]

Traceback (most recent call last):
File "/home/iot/detect.py", line 9, in
ssdnet = cv2.dnn.readNetFromTensorflow('frozen_inference_graph.pb','graph.pbtxt')
cv2.error: OpenCV(4.6.0) /tmp/pip-wheel-u79916uk/opencv-python_ea2489746b3a43bfb3f2b5331b7ab47a/opencv/modules/dnn/src/tensorflow/tf_graph_simplifier.cpp:1052: error: (-215:Assertion failed) permIds.size() == net.node_size() in function 'sortByExecutionOrder'