Error when running watchman

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
echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf
sudo sysctl -p

watchman shutdown-server

This one helped

Increase inotify limit to increase the limit on the number of files you can monitor.

$ echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf
$ sudo sysctl -p

Please go through this for more info

Just run these commands in terminal:

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  

Other Way make Script in package.json

"scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest",
    "flow": "flow",
    "flow-stop": "flow stop",
    "watch-need-help": "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"
  },

Run following command on Terminal in project directory

npm run watch-need-help

This One is Also Helpfull .

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