这对我来说很管用:

react-native start --reset-cache

对于我的问题修复此更改模拟器与API级别低于28。这个问题的根源是API级别28及以上的网络变化。通过添加来解决这个问题

<application
     android:usesCleartextTraffic="true"

对androidManifest.xml

在我的情况下(不使用博览会和Android构建)

package.json

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

和app.json

{
  "sdkVersion": "27"
}

解决问题

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.)

我有同样的问题，而建立我的react原生应用程序的android和我做了以下工作。

错误控制台中“JavaScript版本0.50.1”是包中的react-native版本。json文件。确保它与错误控制台中“本机版本0.50.0”的版本相同。

我已经在错误控制台中按照提示将react-native版本更新为“Native version 0.50.0”。 重新构建应用react-native run-android。

编辑您的包。Json为你的javascript版本

"react-native": "^0.50.1",

后运行

npm install