Useful or not, from you.
react-native Runtime error after upgrade to React Native 0.61 - "TypeError: hmrClient.send is not a function"

I am in the process of updating an existing project from react-native 0.60.4 to 0.61.2. The app is successfully packaged and installs on my local iOS Simulator. The Metro Bundler successfully serves the app to the device. My observations are as follows:

  • Upon running, a red screen error headlined TypeError: hmrClient.send is not a function. is displayed on every launch, regardless of whether Fast Refresh is enabled or disabled.
  • This red screen message can be dismissed, and underneath I have a functional, navigable application.
  • No Fast Refresh functionality works when enabled, most likely tied directly to this.

React Native version:

yarn run v1.19.1
$ /Users/alex/Development/<project>/node_modules/.bin/react-native info
info Fetching system and libraries information...
    OS: macOS 10.15
    CPU: (4) x64 Intel(R) Core(TM) i7-7660U CPU @ 2.50GHz
    Memory: 141.59 MB / 16.00 GB
    Shell: 3.0.2 - /usr/local/bin/fish
    Node: 10.16.3 - /var/folders/t_/q6_rnx915r38lst_z95l6swh0000gn/T/yarn--1571762447670-0.2398560026433516/node
    Yarn: 1.19.1 - /var/folders/t_/q6_rnx915r38lst_z95l6swh0000gn/T/yarn--1571762447670-0.2398560026433516/yarn
    npm: 6.11.3 - ~/.config/nvm/10.16.3/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
    iOS SDK:
      Platforms: iOS 13.0, DriverKit 19.0, macOS 10.15, tvOS 13.0, watchOS 6.0
    Android SDK:
      API Levels: 28, 29
      Build Tools: 28.0.3, 29.0.2
      System Images: android-29 | Google APIs Intel x86 Atom
    Android Studio: 3.5 AI-191.8026.42.35.5900203
    Xcode: 11.0/11A420a - /usr/bin/xcodebuild
    react: 16.9.0 => 16.9.0 
    react-native: 0.61.2 => 0.61.2
Done in 7.47s.

Error output

Simulator Screen Shot - iPhone 11 Pro - 2019-10-22 at 17 39 19

TypeError: hmrClient.send is not a function. (In 'hmrClient.send(JSON.stringify({
        type: 'log-opt-in'
      }))', 'hmrClient.send' is undefined)

    [native code]:0

Other notes

Interestingly, this isn't caught by this preceding invariant statement in the enable or disable members of HMRClient. I suspect it's related to some misalignment within HMRClient.js or any corresponding native code.

That's a useful answer
Without any help

What fixed it for me was to update metro, metro-core and metro-react-native-babel-preset to 0.56 In the end I chose to remove metro and metro-core because it seems they are no longer needed, but just updating them should do the trick