window.webkit.messageHandlers.cordova.postMessage issue

[mgahlan]

using ionic cordova application with angular, recently got this error after upgrading the web view version to 5.0.1

[Error] Unhandled Promise rejection: – "undefined is not an object (evaluating 'window.webkit.messageHandlers.cordova.postMessage')" – "; Zone:" – "" – "; Task:" – "Promise.then" – "; Value:" (2) TypeError: undefined is not an object (evaluating 'window.webkit.messageHandlers.cordova.postMessage') — cordova.js:965 iOSExec — cordova.js:965 execProxy — cordova.js:994 (anonymous function) — mainHandle.js:397 (anonymous function) — storage.js:5 ZoneAwarePromise — polyfills-es2015.js:34327 get — storage.js:4 (anonymous function) — AppRate.js:185 (anonymous function) — AppRate.js:297 build — cordova.js:47 require — cordova.js:62 localRequire — cordova.js:43 (anonymous function) — cordova.js:1194 (anonymous function) — cordova.js:1122 f — cordova.js:675 (anonymous function) — cordova.js:827 (anonymous function) — cordova.js:1114 onScriptLoadingComplete — cordova.js:1862 scriptLoadedCallback — cordova.js:1879 (anonymous function) — cordova.js:1833 wrapFn — polyfills-es2015.js:34585 runTask — polyfills-es2015.js:33534 invokeTask — polyfills-es2015.js:33847 invokeTask — polyfills-es2015.js:34988 globalZoneAwareCallback — polyfills-es2015.js:35014 (anonymous function) (cordova.js:1413) (anonymous function) (polyfills-es2015.js:34026) handleUnhandledRejection (polyfills-es2015.js:34046) (anonymous function) (polyfills-es2015.js:34040) drainMicroTaskQueue (polyfills-es2015.js:33943) invokeTask (polyfills-es2015.js:33851) invokeTask (polyfills-es2015.js:34988) globalZoneAwareCallback (polyfills-es2015.js:35014) [Error] TypeError: undefined is not an object (evaluating 'window.webkit.messageHandlers.cordova.postMessage') runTask (polyfills-es2015.js:33538) invokeTask (polyfills-es2015.js:33847) invokeTask (polyfills-es2015.js:34988) globalZoneAwareCallback (polyfills-es2015.js:35014)