Unexpected token o in JSON at position 1

Ionic Framework ionic-v3
1

I am working on ionic 3 app. when i run it on browser its working fine but when i run as a apk or on mobile it gives me error ‘Unexpected token o in JSON at position 1’ as shown in screenshot https://prnt.sc/q0jxlf . i dont know why its occuring in apk while its working accurately on browser siple ionic serve run.this is my code

register(user)
    {
        return new Promise(resolve => {debugger;

            this.http.post(global.apiUrl + "register", user.value)
            

                // .map(res => res.json())
                  .subscribe(data => {debugger;
                    this.data = data;
                    resolve(this.data);
                },error =>{debugger;
                	let jsonE = JSON.parse(error._body);

						let alert = this.alertCtrl.create({
							title: 'Error!',
							subTitle:jsonE.error,
							buttons: ['OK']
						});
						alert.present();

                    }
                );
        });

please help me i am musch confused