React Native version mismatch

This is what I've done with it:

Close all terminals and run build again.

You may forget to close nodejs terminal from another project, and they happen to have installed different react version.

So the code fetches from nodejs server conflicts with the native one.

In case you created your react-native app using create-react-native-app. You should have a app.json (expo). and a package.json file, check if the expo versions match and change accordingly. For example in my case the problem was that in the app.json file I had a 25.0.0 version for the expo sdkVersion attribute, I change that to 23.0.0 and everything worked.

package.json:

"dependencies": {
    "expo": "^23.0.4",
    "react": "16.0.0",
    "react-native": "^0.50.4"
  }

app.json:

{
  "expo": {
    "sdkVersion": "23.0.0" // before was 25.0.0
  }
}

Just go to your android/app/build.gradle and then add to the dependencies section:

dependencies{
compile ("com.facebook.react:react-native:0.50.3") { force = true } 
}

/// the react native version can be found in package.json

For Android developers who couldn't get it fixed by just closing and rebuilding, Manually uninstall the app on the emulator/device.

just force react native version in your android's app level gradle file, in the dependencies section.

compile ("com.facebook.react:react-native:0.52.0") { force = true }

worked for me

If you're running your React Native app through Expo, upgrading React Native is liable to cause this error (as noted at https://github.com/expo/expo/issues/923).

If that's your scenario, your options are:

Bump Expo (which is listed in your package.json) to a version that is compatible with your React Native version (if one exists, which may not be the case - judging by the linked issue, I figure that Expo support trails React Native releases). Discard your changes, delete and reinstall your Node modules, Eject from Expo, and then (after checking that you can still run your app post-ejection) try your upgrade again.

I've never seen this error before, but whenever I can't get Xcode and React-Native to play well together, I do a couple of things. Check what version of Xcode I'm working with. If it needs to be updated, I update it. Then clearing watchman and the cache are the second place I go. I don't use the reset cache command. It always says that I need to verify the cache, so I skip that (you can do it though, I just get confused). I use rm -rf $TMPDIR/react-* to get rid of any cached builds. If that doesn't work, I try to build the app in Xcode, then work my way from there, to build it with react-native run-ios. With this error message, it seems you might start by trying to build it with Xcode. Hope that helps...let me know your progress with it. Good luck! (Also, you could update to RN 0.51 as another attempt to get your versions synced.)

I had this problem for the longest time and none of the above solutions helped. I was in the middle of upgrading react native in a create-react-native-app project until I found out that not all versions of Expo support the latest React Native.

Found this page linked in the documentation that shows which version combinations of React Native, React, and Expo are officially supported:

Source: https://github.com/react-community/create-react-native-app/blob/master/VERSIONS.md

Editing the app.json and package.json files to match the corresponding versions and running npm install got everything working again.

I am using a physical device, in my case this solved the problem:

Uninstall the app lsof -i :8081 kill -9 PID Rebuild the app (react-native run-android or react-native run-ios)

In your build.gradle file add the following

implementation ("com.facebook.react:react-native:0.51.0") {
    force = true;
}

replace 0.51.0 with the version in your package.json

Try installing the dependencies again. That worked for me-

1.) yarn/npm install
2.) yarn/npm start --reset-cache

For me it was due to react-native version in dependency section of package.json file. It was:

"dependencies": {
"expo": "^27.0.1",
"react": "16.3.1",
"react-native": "~0.55.0"
}

I chaged it to:

"dependencies": {
"expo": "^27.0.1",
"react": "16.3.1",
"react-native": "0.52.0"
}

Now it works fine.

In my case installing a new virtual device helped. Now I am using 1 device per app.

It happens sometimes when you try to run without closing the node server, in which the previous app was running, so try restarting React.To do so, just run the following commands:

1. To kill current processes
killall node -9 

2. To Start React  Native
react-native start 

3. Then Run android
react-native run-android

For my case I'm facing it on iOS, and I've tried to reset and clear all cache using below command but failed too, despite many comments saying that the root cause is there is react packager running somewhere accidentally, I've restarted my mac and the problem still remained.

watchman watch-del-all && rm -rf node_modules/ && yarn cache clean && yarn install && yarn start --reset-cache

The solution is, to delete the build folder @ /ios/build, then execute react-native run-ios solved it

I have tried the solutions above but adding this to AndroidManifest.xml seems to fix it.

  android:usesCleartextTraffic="true"

For others with the same problem on iOS with CocoaPods:

I tried all of the solutions above, without luck. I have some packages with native dependencies in my project, and some of those needed pod modules being installed. The problem was that React was specified in my Podfile, but the React pod didn't automatically get upgraded by using react-native-git-upgrade.

The fix is to upgrade all installed pods, by running cd ios && pod install.

Expo users - make sure your app.json sdk version and package.json expo version are (may be equal) compatible to each other.

The fix we did was to make sure the ANDROID_HOME and PATH variables were set up prior to the build.

First, run the below two commands then the build the app for the device.

export ANDROID_HOME=/Users/username/MyFiles/applications/androidsdk
export PATH=$PATH:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools

This is working for me :

react-native start --reset-cache

edit your package.json for your javascript version

"react-native": "^0.50.1",

after run

npm install

I also had this issue using Expo and iOS Simulator. What worked for me was erasing the Simulator in Hardware > Erase All Content and Settings...

I have got the same issue while building my react native app for android and I did the following which worked for me.

The "JavaScript version 0.50.1" in the error console is the react-native version in your package.json file. Make sure it is the same version as "Native version 0.50.0" in the error console.

I have Updated the react-native version to the "Native Version 0.50.0" as prompted in the error console. Rebuild the app react-native run-android.

Possible Fix:

Delete the package-lock.json Run: watchman watch-del-all && rm -rf $TMPDIR/react-* && rm -rf $TMPDIR/haste-map-react-native-packager-* && rm -rf node_modules/&& npm install

If the problem persists, try to execute the project directly from the Xcode

This worked for me.

In my case (NOT using expo & Android build)

package.json

"dependencies": {
    "react": "16.3.1",
    "react-native": "0.55.2"
}

And app.json

{
  "sdkVersion": "27"
}

resolved the issue

I was trying to build and run a React Native app from WebStorm and ran into this problem. The simple solution for me was:

watchman watch-del-all

On macOS, if watchman is not already installed, install it using Homebrew:

brew install watchman

In my case, I changed the expo version manually. I got the same issue because I forgot to update sdkVersion in app.json and babel-preset-expo in package.json

After that run: expo r -c to clear cache and start the app.

This Answer is Published in 2020, Fix this Error in 3 steps:

First step: I changed the value of expo in package.json file to the latest supported version, according to expo documents(visit here).

Second step: I changed the value of sdkVersion in app.json file to the same value of expo in package.json.( equal number to last step).

Third step : I changed the value of react-native in package.json file to the same value of React Native Version , according to expo documents(visit here).

now your ready to go.

use npm install to install specified version of dependencies and then npm start to run the project

I got this classing when TypeScript type definitions mismatched.

E.G react-native at 0.61.5 in dependencies and @types/react-native at 0.60.0 in devDependencies.

As soon as I updated devDependencies it worked. Didn't have to restart anything.

For me, who is running with a monorepo, there was a hidden react-native version inside yarn.lock. It was not present in any package.json, but was never deleted.

I removed that particular react-native version from yarn.lock, and did a

yarn install

This cleaned out alot of old stuff and made sure that things was working fine.