CaptureScreenshot WebGL

Hi,

I'm trying to Capture a screenshot of my game to use in the user interface. Loading a texture from resources and using it on a plane already works.

capturing a screenshot works in the editor, but when I build for WebGL I keep receiving the error "Failed to store screen shot" and I have no idea how to fix it. Tried a few things already, but none seem to work.

Here you can see my code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class DebugUser : MonoBehaviour
 {
     public Material MatScreenshot;
 
     // Use this for initialization
     void Start ()
     {
         
     }
     
     // Update is called once per frame
     void Update ()
     {
         if(Input.GetKeyDown("j"))
         {
             ConfigurationManager.Instance.ConfigurationToJson();
         }
 
         if (Input.GetKeyDown("l"))
         {
             ConfigurationManager.Instance.JsonToConfiguration(null);
         }
 
         if (Input.GetKeyDown("t"))
         {
             ScreenCapture.CaptureScreenshot(Application.dataPath);
         }
 
         if(Input.GetKeyDown("y"))
         {
             Texture screenshot = Resources.Load("UnityScreenshot") as Texture;
             MatScreenshot.SetTexture("_MainTex", screenshot);
         }
     }
 }