React Native DuplicateError: Duplicated files or mocks

Solution 1:

The cause for me was that I had two different package.json files with the same value for the name property.

Solution 2:

I had took back up of node_module back in project root as "xnode_module". So I have delete back up, it works for me.

Solution 3:

cd ios/
rm -rf build/
xcodebuild clean
cd ..
react native run ios

or check inside project you have must same name project inside

Solution 4:

Because you have two package.json file in your project like package.json and another\\package.json in a sub directory. Also you've get more information on your terminal and in most of times it contains the path :

All you have to do is delete the duplicated file in sub directory Not Main file.