[ionic] ionic Common Error Summary

Uncaught (in promise): TypeError: Cannot read property 'nativeElement' of undefined
TypeError: Cannot read property 'nativeElement' of undefined
    at new MapPage (http://localhost:8100/build/main.js:70:48)
    at createClass (http://localhost:8100/build/vendor.js:12857:20)
    at createDirectiveInstance (http://localhost:8100/build/vendor.js:12700:37)
    at createViewNodes (http://localhost:8100/build/vendor.js:14158:53)
    at createRootView (http://localhost:8100/build/vendor.js:14047:5)
    at callWithDebugContext (http://localhost:8100/build/vendor.js:15472:42)
    at Object.debugCreateRootView [as createRootView] (http://localhost:8100/build/vendor.js:14755:12)
    at ComponentFactory_.create (http://localhost:8100/build/vendor.js:11652:46)
    at ComponentFactoryBoundToModule.create (http://localhost:8100/build/vendor.js:4404:29)
    at Tab.NavControllerBase._viewInit (http://localhost:8100/build/vendor.js:51917:44)

C:\project\android\myApp>ionic cordova platform  add browser
> cordova platform add browser --save
Using cordova-fetch for cordova-browser@~5.0.1

(node:292) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): CordovaError: Failed to fetch platform cordova-browser@~5.0.1
Probably this is either a connection problem, or platform spec is incorrect.
Check your connection and platform name/version/URL.
Error: cmd: Command failed with exit code 4294963248 Error output:
npm ERR! path C:\project\android\myApp\node_modules\fsevents\node_modules
npm ERR! code EPERM
npm ERR! errno -4048
npm ERR! syscall lstat
npm ERR! Error: EPERM: operation not permitted, lstat 'C:\project\android\myApp\node_modules\fsevents\node_modules'
npm ERR!  { Error: EPERM: operation not permitted, lstat 'C:\project\android\myApp\node_modules\fsevents\node_modules'
npm ERR!   stack: 'Error: EPERM: operation not permitted, lstat \'C:\\project\\android\\myApp\\node_modules\\fsevents\\node_modules\'',
npm ERR!   errno: -4048,
npm ERR!   code: 'EPERM',
npm ERR!   syscall: 'lstat',
npm ERR!   path: 'C:\\project\\android\\myApp\\node_modules\\fsevents\\node_modules' }
npm ERR!
npm ERR! Please try running this command again as root/Administrator.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\itsvse_pc\AppData\Roaming\npm-cache\_logs\2018-07-04T06_03_57_026Z-debug.log
(node:292) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.