RNFetchBlob requires main queue setup

Question

When using RNFetchBlob with React Native I get a yellow warning screen that says:

Module RNFetchBlob requires main queue setup since it overrides constantsToExport but doesn't implement requiresMainQueueSetup. In a future release React Native will default to initializing all native modules on a background thread unless explicitly opted-out of.

I am using react-native 0.56.0 and react-native-fetch-blob: 0.10.8. This worked previously with react-native 0.54.2.

What exactly is this error telling me? What exactly is main queue setup? What should I do to fix this problem? Thanks!

Related but not completely answers your question: https://stackoverflow.com/q/50929930/2315280 — bennygenel, Jul 15 '18 at 07:40

score 39 · Accepted Answer · answered Jul 15 '18 at 20:49

39

It turns out that react-native-fetch-blob is no longer supported and I needed to use rn-fetch-blob instead. To fix this I had to do the following:

react-native unlink react-native-fetch-blob
npm uninstall --save react-native-fetch-blob
npm install --save rn-fetch-blob
react-native link

I then had to change all lines that used:

import RNFetchBlob from 'react-native-fetch-blob';

to:

import RNFetchBlob from 'rn-fetch-blob';

Everything is now working the way that it should.

answered Jul 15 '18 at 20:49

kojow7

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This should be the accepted answer. For iOS please not that you have to run pod install in the iOS folder for it to work. – Florian Oct 03 '18 at 16:08
rn-fetch-blob is also no longer maintained, use react-native-blob-util instead – Nathan Tew Jul 19 '23 at 04:41

score 2 · Answer 2 · answered Nov 10 '20 at 19:52

2

If you are using react native 0.63.3, after replacing react-native-fetch-blob with rn-fetch-blob there is no link command, so don't forget to execute pod install in ios directory.

answered Nov 10 '20 at 19:52

Kasra

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This should be the updated answer for modern RN. – Nick.D Jul 08 '21 at 21:00

RNFetchBlob requires main queue setup

2 Answers2