CODE EXAMPLE FOR SHELL

react native cannot connect to metro server

echo 256 | sudo tee -a /proc/sys/fs/inotify/max_user_instances
echo 32768 | sudo tee -a /proc/sys/fs/inotify/max_queued_events
echo 65536 | sudo tee -a /proc/sys/fs/inotify/max_user_watches
watchman shutdown-server

 Or
 
 echo 999999 | sudo tee -a /proc/sys/fs/inotify/max_user_watches && echo 999999 | sudo tee -a /proc/sys/fs/inotify/max_queued_events && echo 999999 | sudo tee -a /proc/sys/fs/inotify/max_user_instances && watchman shutdown-server && sudo sysctl -p