Solution 1:

For React Native Init approach (without expo) use:

npm start -- --reset-cache

Solution 2:

Simplest one(react native,npm and expo )

For React Native

react-native start --reset-cache

for npm

npm start -- --reset-cache

for Expo

expo start -c

Solution 3:

Clearing the Cache of your React Native Project:

npm < 6.0 and RN < 0.50:

 watchman watch-del-all && rm -rf $TMPDIR/react-* &&
 rm -rf node_modules/ && npm cache clean && npm install && 
 npm start -- --reset-cache

npm >= 6.0 and RN >= 0.50:

 watchman watch-del-all && rm -rf $TMPDIR/react-native-packager-cache-* &&
 rm -rf $TMPDIR/metro-bundler-cache-* && rm -rf node_modules/ && npm cache clean --force &&
 npm install && npm start -- --reset-cache

Solution 4:

try this

react-native start --reset-cache

Solution 5:

For those who are using expo-cli

expo start -c