Bundlejs error on release build in Xcode (react-native) - ios

Question

For some reason I am getting the following error when building a release version of my application via react-native.
*** Terminating app due to uncaught exception 'RCTFatalException: Unhandled JS Exception: t.typeof is not a function. (In 't.typeof("function"==typeof Symbol?Symbol.iterator:"##iterator")', 't.typeof' is undefined) (/Users/../THEAPP.app/main.jsbundle:11)', reason: 'Unhandled JS Exception: t.typeof is not a function. (In 't.typeof("function...'
This is the source of the code that has the above error that I found in my bundlejs file:
!(function(e){"use strict";var r,t=e.babelHelpers={};t.typeof="function"==typeof Symbol&&"symbol"===t.typeof("function"==typeof Symbol?Symbol.iterator:"##iterator")?
I have tried both of these methods of a release build:
Making bundle by editing the Scheme to be a Release bundle
Export a bundle myself by using the following: react-native bundle --entry-file index.js --platform ios --dev false --bundle-output ios/main.jsbundle --assets-dest ios
I get the same error for both of these. And of course, this is after I change my AppDelegate.m to the following:
//jsCodeLocation = [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:#"index" fallbackResource:nil];
jsCodeLocation = [[NSBundle mainBundle] URLForResource:#"main" withExtension:#"jsbundle"];
I also followed someone's response from Github issues and tried the following, but got another separate issue entirely after the fact:
I did:
npm uninstall -g babel-preset-env
npm install --save #babel/preset-env
Added this to my package.json file
"babel": { "presets": ["#babel/preset-env", "react-native"] }
And created a .babelrc file in my root project with:
{ "presets": ["#babel/preset-env", "react-native"] }
Then get this on an Xcode build:
Environment
OS: macOS High Sierra 10.13.4
Node: 9.11.1
npm: 5.6.0
Watchman: 4.9.1
Xcode: Version 9.4 (9F1027a)
react: 16.3.1
react-native: 0.55.4

Answer 1

I solved this by completely restarting my app and using:
react-native init PROJECTNAME