[WP8.1] WebcamTexture won't play

The code

 this.texture = new WebCamTexture();
 this.texture.Play();

Causes the error

 Error: operation has failed with error 0x80028019: old format or invalid type library.
 (C:/Buildslave/unity/build/PlatformDependant/MetroPlayer/VideoTexture.cpp:WebcamTexture::Play at 388)

and won't play the webcam texture.

Player settings:

• webcam and microphone access are enabled

• compilation overrides is set to "none"

• API compatibility level is .net 2.0

Build settings:

• Build target: windows store

• SDK: Phone 8.1

• development build

the rest is pretty much kept at the default settings, there is 1 script, a panel and a preview texture on screen

here's the full code of the script:

 using UnityEngine;
 using System.Collections;
 using UnityEngine.Events;
 using UnityEngine.UI;
 
 public class FindCameras : MonoBehaviour
 {
     public RawImage preview;
     public GameObject templateButton;
     private WebCamTexture texture;
 
     // Use this for initialization
     void Start () {
         foreach ( var child in GetComponentsInChildren<Transform>() )
         {
             if(!child.gameObject.name.Equals("Panel"))
             Destroy(child.gameObject);
         }
         for ( int i = 0; i < WebCamTexture.devices.Length; i++ )
         {
             GameObject button = Instantiate ( templateButton );
             Button actualButton = button.GetComponent < Button>();
             Button.ButtonClickedEvent evt = new Button.ButtonClickedEvent();
             int i1 = i;
             evt.AddListener(
                             () =>
                             {
                                 texture.Stop();
                                     this.texture = new WebCamTexture(WebCamTexture.devices[i1].name);
                                     preview.texture = texture;
                                 this.texture.Play();
 
                             } );
 
             actualButton.onClick = evt;
             button.GetComponentInChildren < Text > ().text = WebCamTexture.devices [ i1 ].name;
             button.transform.parent = transform;
         }
 
         this.texture = new WebCamTexture();
         this.texture.Play();
         preview.texture = texture;
     }
     
     // Update is called once per frame
     void Update () {
 
     }
 }