Hello NILESH KUMAR TIWARI,Greetings and Welcome to the Google Chrome Enterprise Help Community. ERR NETWORK CHANGED usually appears with an error message reading "Unable to access the network" . As you can see, the error code ERR_NETWORK_CHANGED broadly points to some kind of Network connectivity issues on your computer and does not provide any specific reason for the problem.
Try a quick browser reset in case a setting or extension is causing the issue
Reset Chrome settings to default. If that fixes the issue add your extensions back 1 at a time so that if the problem reoccurs you know which extension caused it.
Hope it helps. Thank you..!