Upgrade ionic2 and got Promise Rejection Error, how can I debug?


Hey there,

I juste upgrade my ionic 2 version and now when I want to “ionic serve” I get this error :

(node:29658) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): TypeError: Cannot read property ‘content’ of null

My project is a quite big and the error is not really helpful. How can I debug my project efficiently ?



Are you using the newest ionic-app-scripts version? check your package.json.


Yes :

“scripts”: {
“clean”: “ionic-app-scripts clean”,
“build”: “ionic-app-scripts build”,
“ionic:build”: “ionic-app-scripts build”,
“ionic:serve”: “ionic-app-scripts serve”


i mean are you using the latest version of app-scripts

"devDependencies": {
    "@ionic/app-scripts": "1.0.0",



"devDependencies": {
    "@ionic/app-scripts": "0.0.47",
    "typescript": "2.0.9"