error when i create new react-native-project-app, mac terminal?

Question

i have a project in react-native. When I run react-native run-ios on the mac terminal, I get this error:[enter image description here][1] I'm running on: react-native-cli: 2.0.1 react-native: 0.55.4 node 8.12.0 nom 6.4.1

error: bundling failed: NotFoundError: Cannot find entry file index.js in any of the roots: ["/Users/=========/my-app"]

at DependencyGraph.getAbsolutePath (/Users/=========/my-app/node_modules/metro/src/node-haste/DependencyGraph.js:317:11)

at /Users/=========/my-app/node_modules/metro/src/DeltaBundler/DeltaCalculator.js:280:416

at Generator.next (<anonymous>)

at step (/Users/=========/my-app/node_modules/metro/src/DeltaBundler/DeltaCalculator.js:11:445)

at /Users/==========/my-app/node_modules/metro/src/DeltaBundler/DeltaCalculator.js:11:605

at <anonymous>

at process._tickCallback (internal/process/next_tick.js:189:7)

BUNDLE [ios, dev] ./index.js ░░░░░░░░░░░░░░░░ 0.0% (0/1), failed.