Jetson detectnet-camera.py will not run?

When trying to run detectnet-camera.py I get the following…

jetson.inference.init.py
Traceback (most recent call last):
File “/home/john/Desktop/MyPython/detectnet-camera.py”, line 24, in
import jetson.inference
File “/usr/lib/python3.6/dist-packages/jetson/inference/init.py”, line 4, in
from jetson_inference_python import *
ImportError: libjetson-utils.so: cannot open shared object file: No such file or directory

What is wrong?
What shared object file?

I understand Python but not this…
John

Duplicated with https://devtalk.nvidia.com/default/topic/1063178/camera-demos-seem-to-fail-due-to-not-finding-imports-/