--- title: Troubleshoot React Native source maps and JavaScript errors source: https://docs.newrelic.com/docs/mobile-monitoring/new-relic-monitoring-react-native/troubleshoot-react-native-source-maps --- Use this page to troubleshoot React Native source map uploads and `MobileJSError` symbolication. To learn how to upload source maps, see [React Native JavaScript error reporting](https://docs.newrelic.com/docs/mobile-monitoring/new-relic-monitoring-react-native/react-native-agent-js-error-reporting). ## Troubleshooting [#troubleshooting] ### Source map errors in the UI [#sourcescontent] If you see any of the following errors in the UI, either your source map file is missing the `sourcesContent` attribute, or the metadata submitted with the upload (`sourcemapName`, `jsBundleId`, or `appVersion`) doesn't match the values the app reports for that build: - `Source map not found.` - `Source map missing.` - `Incorrect map detected.` - `Incorrect and missing maps detected.` First, confirm the `sourcemapName`, `jsBundleId`, and `appVersion` used for the upload match the values the app reports for that build (see [Why don't my line numbers match?](#faq-line-numbers)). If the metadata matches, your source map must include the `sourcesContent` attribute for New Relic to un-minify your stack traces. Regenerate the source map so it includes this attribute, then upload it again. Most bundlers include the original source content when you enable an option such as `includeSources` (or the equivalent for your build tool). ### You have a React Native app but don't see the menu item [#no-menu-item] If you have a React Native app but don't see the React Native menu item in the UI, check that you're on an updated agent version and that your app is sending data. The menu item doesn't appear until the app sends data tagged with the React Native platform. ### You don't see both MobileJSError and handled exception events [#mobilejserror-events] With the new agent version, you won't see both `MobileJSError` events and handled exception events for the same JavaScript errors. JavaScript errors are recorded as `MobileJSError` events instead. New Relic currently supports `MobileJSError` for React Native only. Capacitor and Cordova aren't supported. ## Frequently asked questions [#faq] **Does New Relic accept zipped files?** Yes. You can upload a gzipped or zipped (`.zip`) source map. The build scripts automatically zip large `.map` files before upload. **What is the maximum upload payload size?** 200 MB unzipped. New Relic doesn't store source maps larger than 200 MB unzipped for symbolication. It sends build telemetry instead. For details, see [File size limitations](https://docs.newrelic.com/docs/mobile-monitoring/new-relic-monitoring-react-native/react-native-agent-js-error-reporting#file-size-limitations). **Why don't I see code snippets in my stack trace?** Code snippets require the `sourcesContent` attribute in your source map. If your source map doesn't include the original source content, New Relic can still un-minify the stack trace using line and column mappings, but it can't display the surrounding source code. Regenerate the source map with an option such as `includeSources` enabled (or the equivalent for your build tool), then upload it again. **Why don't my line numbers match?** Line numbers don't match when the uploaded source map doesn't correspond exactly to the JavaScript bundle that produced the error. Make sure the `jsBundleId` and `appVersion` used for the upload match the values the app reports for that build — this is especially important after a CodePush or other over-the-air (OTA) update, when the JavaScript bundle diverges from the native binary version. Also confirm your source map is version 3. **Why aren't my files symbolicated?** Common causes include: - The source map is missing the `sourcesContent` attribute (see [Source map errors in the UI](#sourcescontent)). - The `jsBundleId` or `appVersion` don't match between the upload and the running app (see [Why don't my line numbers match?](#faq-line-numbers)). - The source map exceeded the [200 MB limit](#faq-size), so New Relic only sent build telemetry. - The data hasn't finished syncing yet. After an upload it can take a few minutes for the data to become available. - The source map's API key and the application token belong to different New Relic accounts. **How can I see what I uploaded to New Relic?** Use the list command in NerdGraph or NRQL. See [List and delete React Native source maps](https://docs.newrelic.com/docs/mobile-monitoring/new-relic-monitoring-react-native/list-delete-react-native-source-maps). **Can I upload multiple source maps for a multi-bundle app?** No. New Relic's React Native symbolication supports only a single source map file, matching Metro's default (non-multi-bundle) symbolicator. If your app splits its JavaScript into multiple bundles and generates multiple source maps, New Relic doesn't support symbolication for that setup. If this is affecting you, [contact New Relic Support or file a feature request](https://docs.newrelic.com/docs/mobile-monitoring/new-relic-monitoring-react-native/react-native-agent-js-error-reporting#request-support) to request multi-bundle support.