Could not connect to development server. Using Android emulator.

[joshg111]

I just started a new project, with latest version of node.js, react, react-native, react-native-cli. My old projects were using some older versions of those packages and were working fine.

react-native init
cd
react-native run-android

I see the app gets installed on the emulator. When the app launches on the emulator after some time it give the error "Could not connect to development server".

My package.json:

{
  "name": "MyProjectName",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start"
  },
  "dependencies": {
    "react": "15.2.1",
    "react-native": "0.30.0"
  }
}

Output of "adb devices":

List of devices attached
emulator-5554   device

My Android sdk's are fairly new, but maybe I will try to reinstall all that stuff per react-native docs.

Btw, the react-native docs don't specify how to start the emulator. I start the emulator by launching Android Studio, and opening the AVD manager. This approach seems to work with my old projects.

Please let me know what other information is needed.

[joshg111]

Also, the packager server is running on port 8081.

[joshg111]

I think typically there is a request sent by the emulator when it is "Fetching JS Bundle" and that request is logged in stdout of the packager server, but now I do not see any request hitting the server.

[joshg111]

Turns out the TermService was using port 8081. Imo react native packager server should throw an error if another process is using the port it wants.

Ticket can be closed.

[brookehurford]

@joshg111 Could you explain what you mean by TermService - or how you ended up fixing this? I am experiencing the same issue but have little experience on Android.

[joshg111]

I'm on windows so I ran some command to get used ports.
netstat -a -b > out

Then I opened "out" and found that the TermService was using port 8081. TermService is used for windows remote desktop protocol. Turns out I coincidentally used port 8081 for remote desktop setup and didn't realize it would conflict with react native. I changed the port for remote desktop back to the default in regedit, and restarted, then everything worked fine.

[WillyRamirez]

@joshg111 for me it was also the port... potgresSQL.exe, for months and months i have been working on emulator and downloading 'release' apk's to my phone because debugger couldn't connect. Thanks Josh!!!