React Native App with Expo - QR code not loading - react-native

Question

I'm following this tutorial:
https://blog.expo.io/building-a-react-native-app-using-expo-and-typescript-part-1-a81b6970bb82
yarn global add create-react-native-app
create-react-native-app my-app-name
cd my-app-name
yarn start
I am on the same network as my phone (Android). No VPN. I am in the root folder of my app. It says Loading dependency graph, done. so I know it's running.
Firewall is also off for this as well and this is not a timeout error.
When I scan the QR code:
Something went wrong. Could not load exp://10.0.0.21:19000.
What could be my issue?
EDIT
New error: Uncaught Error: java.net.ConnectException: Failed to connect to /10.0.0.21.19000

Answer 1

Try opening the debugger in chrome and then select tunnel if your device and the development pc are not connected to the same server.

Answer 2

Try the Enter URL manually option
First make sure you are on the same wifi ( computer || laptop and mobile device)
Second open cmd and run command ipconfig their you will get IPv4 Address copy it
Go to your expo go app tap on Enter URL manually
Enter exp://your_IPv4_Address:19000 ( Example -- exp://192.168.1.38:19000 )
Connect now -- It should work

Answer 3

In my case, I used tunnel and there was a problem with the sdk version - I have 39.0.0 and I should use only 36, 37 or 38 - that is the message that i have got from expo, so all I did is to get into the app.json file, and add the following line in expo (or just change it if it already exist):
"sdkVersion": "38.0.0"
and it should look like:
"expo": {
"name": "DoneWithIt",
"slug": "DoneWithIt",
"sdkVersion": "38.0.0",
"version": "1.0.0",
....
....
}
In the package.json file in dependencies, change the version to 38.0.0 in "expo" and "react-native" :
"dependencies": {
"expo": "~38.0.0",
"expo-status-bar": "~1.0.2",
"react": "16.13.1",
"react-dom": "16.13.1",
"react-native": "https://github.com/expo/react-native/archive/sdk-
38.0.0.tar.gz",
"react-native-web": "~0.13.12"
}
then run:
cd yourAppName
npm start
and it will be loaded on your phone.
you can watch it from here:
https://www.youtube.com/watch?v=eS8VULijAZ4
In this video he uses 32.0.0 so be aware to the updated version (in my case 38.0.0 was good for 09/2020)

Answer 4

Just delete the node_modules folder from your application and then run npm install to get the dependencies.
Now run expo start or npm start, the QR code will load now.

Answer 5

On node v12.18. In the package.json downgrade expo and react-native connector. 38 works instead of 40.
"expo": "~38.0.0",
"react-native": "https://github.com/expo/react-native/archive/sdk-38.0.0.tar.gz",
Then remove node_modules and reinstall them
rm -rf node_modules
npm install
then run again :
npm start
QR should work this time

Answer 6

I had this problem after and expo update. Instead of running
npm/yarn start
(executes expo start --dev-client)
Try
npm run run
(executes expo start)

Answer 7

run the command
expo start --tunnel