Invalid character

After upgrading to ionic 3.9.2 I am getting Invalid character error ` in IE11. Though the app is working fine on Chrome/Safari/Edge.

Here is the ionic setup details :

 @ionic/cli-utils  : 1.18.0
  ionic (Ionic CLI) : 3.18.0

global packages:   cordova (Cordova CLI) : 7.0.1

local packages:
    @ionic/app-scripts : 3.1.0
    Cordova Platforms  : ios 4.4.0 windows 5.0.0
    Ionic Framework    : ionic-angular 3.9.2

System:

    Node : v8.9.1
    npm  : 5.5.1
    OS   : Windows 10

Any help what might be the issue?

Thanks in advance,
Tarak