When I run my react-native app I can't see my logs.
The device where I started it doesn't even show up in the list. I tested it with iOS, android and an simulator. Any suggestions?
I use the following expo versions:
"expo": "^40.0.0",
"expo-cli": "3.28.6",
You can override console functions like console.log and that can completely change the way they work, it can also intend to do nothing and just disable the log in these cases just remove the libraries you installed recently or restore your project to the point the console worked then find the problem and fix it.
In my case I was running the app on an emulator on my local machine.
What solved it for me was changing the connection setting from LAN to LOCAL.
Either change it through the expo developer tools or just run expo start --localhost instead of expo start
Change a device name to English!
After the npm start, when the android simulator is open and running with Pixel3, if I 'click' a (for Android emulator), this error appears and the app does not open on the emulator
Trying to open the project on Android...
Installing Expo on device
-Couldn't start project on Android: Error running adb: Failed to install C:\Users\Atif\.expo\android-apk-cache\Exponent-2.16.1.apk:
Expo Press ? to show a list of all available commands.
|
This download is taking longer than expected. You can also try downloading the clients from the website at https://expo.io/tools
I also tried uninstalling and install again. Also I Tried Opening the emulator then run npm start.
Hope Someone Help me. But for whoever helped me i will appreciate their help. Thanks in Advance !!!
first, turn off AVD , then restart start the system, and open AVD and expo project. it will work mostly. If not delete the previous Pixel3 device , restart the system and take a new device and try.
This is because of access issue to open the emulator. Can you manually start a emulator device open, and check react-native run- android. Hopefully if the app is happy, it will install on the emulator.
I am working on an App in RN and when trying to run either an Android Emulator or Webpack the error 'Expo not defined' pops up. I have had my instructor look over the code and he hasn't quite figured it out either. The first time I was able to get it working by restarting my computer as well as re-installing node-modules. Any advice? Here is a screenshot.Expo not defined
it looks like you have some code in MainComponent.js that calls Expo.Constants.statusBarHeight - you should remove that
Are you importing Expo in top of file?
import Expo from 'expo';
Can you install expo again?
npm install expo
if u r compiling the code on web then ofc it will show error on expo being undefined but check that app on mobile running expo app it will run there without any error .
Hope it solved your problem
I use react-native with actual version and have tried to create a simple project. But while trying to create it by using
expo init AwesomeProject
the whole process hangs.
I have tried to look for a solution by searching on the internet but without any luck.
The error could be seen in the following screenshot:
That error generally means that a file is being accessed by two different things at 'around' the same time. And 90% of those times it is because of an anti-virus or similar.
Its a permission error, so my advice, try to do it after a fresh reboot and boot the powershell as admin, disable antivirus etc..
If still does not work reinstall nodejs/npm.
I had the same experience. The project gets created using React-native. When you try to run it, the 'Metro' interface comes up. There is an android phone on the USB drive which has previously been used to run Android Studio created projects successfully. However, on the command shell the app hangs in Metro.
While trying to run the project from Android Studio snow cat, there are build errors (red) in the App manifest file and there is this exception.
Build failed due to java.lang.NullPointerException
Installed expo-cli (C:\Reactive-native>npm install -g expo-cli). The app fails to run and hangs on the connected Android phone(Samsung 21) using the Expo Go client. This client has no problem having been tested in Snackbar.
I have a question in the Expo forum and probably someone will answer!
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