Ionic2 Uncaught (in promise): Error: Malformed UTF-8 data .... jwt , encrypt , decrypt


i am a newbie for ionic2 … please guide to me how can i fix this problem …

on my express api this is my code.

this on my ionic2 application provider api

this is my ionic 2 application show page ( ngOnInit )

this is a result before decrypt and error when i decrypt

help me pleaseeee …//
older i use ionic2 beta 11 i don’t have this problem