Whenever i start expo with expo start command, this error appears
Error: Cannot find module 'metro-core'
Require stack:
- /usr/local/lib/node_modules/expo/node_modules/#expo/cli/build/src/start/server/metro/instantiateMetro.js
- /usr/local/lib/node_modules/expo/node_modules/#expo/cli/build/src/start/server/metro/MetroBundlerDevServer.js
- /usr/local/lib/node_modules/expo/node_modules/#expo/cli/build/src/start/server/DevServerManager.js
- /usr/local/lib/node_modules/expo/node_modules/#expo/cli/build/src/start/startAsync.js
- /usr/local/lib/node_modules/expo/node_modules/#expo/cli/build/src/start/index.js
- /usr/local/lib/node_modules/expo/node_modules/#expo/cli/build/bin/cli
I have tried to reinstall metro-core, but with no effect.
So, does anyone know the solution ?
you are running expo start, try run
npx expo start
This should work.
Let me know if this works.
I had uninstalled React Native and installed it again. Then, it worked!
Also, there were some network issues when I scan the QR code using expo go app. The solution was to change the connection from LAN to tunnel using expo start --tunnel command.
I am new to react-native or you can say new to React and I am working on react-native navigation I have installed all the required libraries as instructed in https://reactnavigation.org/docs/getting-started but when I am running my code it is giving an error as '#react-navigation/native could not be found within the project or in this directories.' What should I do is there any way to get started with my code? Help me
If you have installed your app following the react native cli guide you might want to try running
gradle clean
in your android folder und then try to run your app in the emulator again.
On my first steps with react native I stumpled upon the same issue. :-)
I am fairly new to React Native. I am building a basic app using expo-cli. I don't have a deep understanding on how it works, but I've been following tutorials online on how to use it. Today, I was working on it and used 'npm start' command to launch the expo portal so I could demo my app on a virtual machine but it says it can no longer find the link to the .json file. Can someone please help me to get it working again.
Looks like you're one directory up? Try cd WhatsUp and then run npm start again.
yesterday my application was running very well I closed it when I open my project in vs code and run npm start and open an android studio and open emulator I connected it again but this error comes on emulator.
It looks like your app was made with expo. Instead of npm start, use expo start. I've had a similar problem where the JavaScript bundle keeps building over and over. I solved it by restarting the app.
If this doesn't work, try restarting your pc.
Hope this helps :)
I think it's because of require() or try restarting your pc.
React Native app crashing without any error log. No output on "react-native log-android" terminal, no red screen with error, Android emulator just crashes. Tried running with Expo, again crashes with no error
Happens when working with TextInput. I have some ideas how I can fix the code, but want to understand why is app crashing without error log and making debugging much more difficult?
my bug was fixed by deleting the build folder(inside android/app) and running
npx react-native run-android
Run adb logcat
You can find your app name in your package.json, under the name field.
Also when looking for errors specifically dealing with react native, try running
adb logcat | grep 'redbox'
This way you don't have to scan the entire logfile.
Or try the method shown in this article:
Run adb logcat *:S ReactNative:V ReactNativeJS:V in a terminal to see your Android app's logs.
I was running an Android Project on my Linux PC, then I have made some changes on it in a MacOS PC, and when I git pulled de project back to Linux I faced that crashes
inside the android folder, just run:
./gradlew clean
and then try to run it again.
In case none of these work, don't hesitate to just filter on Warning or Higher as sometimes there will be a low level error that will not be caught by the RN filters.
I was only able to find my issue(s) with the following:
adb logcat '*:W'.
In case react native app crashes without an error message checking the problem in Android Studio's Logcat works perfect. But don't forget to create a filter with your package name.
Open Android Studio
Open Logcat
Click on "Edit Filter Configuration" in the right top of the logcat screen
Fill in your criteria (don't forget package name)
Run you react native project on an android device or emulator
This may be because SOLoader is absent.
Ensure
implementation'com.facebook.soloader:soloader:0.9.0+'
is added under dependencies in android/app/build.gradlle
clean your build
cd android
./gradlew clean
Try bundling
./gradlew bundleRelease
Exit android folder
cd ../
Try running
npx react-native run-android --variant=release
My app kept crashing because I had changed the name of the app in a few places. Make sure your app name is the same everywhere.
Check if the folder name in
android/app/src/main/java/com/<appname>
has the same name as that of your app in manifest file in
android/app/src/main/
My RN App works correctly before, suddenly one day it does not work, keeps crashing without error log. All I have to do is: delete build and .gradle folder under android folder, then run again, it works. Hope it may help someone.
this worked for me
run react-native start --reset-cache
after this if app throws some import error kill the task and run react-native start or npm start normally and open the app.
Deleting my node_modules, reinstalling them and run
npx react-native run-android
fixed it for me
While running your Android Emulator for debugging also run
Android Studio -> Tools -> Android -> Android Device Monitor
It will tell you exactly what is crashing the app under LogCat tab.
two easy steps solved my problem...
open android studio and remove offline bundle from src/main/assest..(** if any)
open MainApplication.java and remove the following import..
import com.facebook.react.BuildConfig
I had the same issue, maybe you made the same mistakes i did.
Make sure u didn't change the app's package name (ex: com.myapp.app).
I lost a lot of time on this. Seems like someone else published a app with the same name on google play, and i didnt change it correctly in each place i should on mine.
Anyway, if that is not your problem, it is probably in something u changed in build.gradle or other config file, try to remember where u last changed something.
Was having this issue on Windows 10
What fixed it for me in the end was:
delete C:\Users\%userprofile%\.gradle\caches
deleteyour-react-app/android folder completely - then 'Discard Changes' in git so you get the original files back
re-run npx react-native start and npx react-native run-android
A tip, my emulator api version was 32. And my targetSdkVersion was 31.
I created another emulator which api level is 31 and the error is gone.
Well first of all, does it crashes when it opens or does it crash at a specific screen? Mine crashed because I did not put my text inside <Text></Text> inside the TouchableOpacity
a very simple solution for me.
delete this file -> gradle-wrapper.properties
and run android folder with android studio.
In case you tried any of the given suggestions and none worked, use Android Studio to run the app in debug mode and then watch logs at the debug console.
For me, it was a styling rule error. I did
paddingTop: Platform.OS === 'ios' && 50 which caused the app to exit immediately on Android.
The debug console log I got was E/unknown:ViewManager: Error while updating prop paddingTop
To correct that, I did paddingTop: Platform.OS === 'ios' ? 150 : 0
Delete Your node modules
Then run npm install
after this run
for window
gradlew clean
for macOS
./gradlew clean
then run
npx react-natie run-android --variant-release
or
npx react-natie run-android