In Unity, line of code keeps blocking video in WebGL? - unity3d

Question

I want to play a video in WebGL but it keeps blocking my video due to one line of code and I don't know why or how to "repair" it. When clicking on play, only one frame is shown and then it stops. (Entire code below).
The issue is this particular line in my Update function:
if (video.isPlaying)
{
if (!video.isPrepared) return;
videoSlider.value = (float)NTime; //This line here!!!
}
If not commented out, the video wont play, for whatever reason.
NTime, which seems to cause the issue, is:
video.time/ ((ulong)(video.frameCount / video.frameRate)) //video is videoPlayer
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Video;
using TMPro;
public class SliderVideo : MonoBehaviour
{
[SerializeField] VideoPlayer video;
[SerializeField] Slider videoSlider;
[SerializeField] Slider volumeSlider;
[SerializeField] Button playButton;
[SerializeField] RawImage fullScreenImage;
[SerializeField] RectTransform buttons;
[SerializeField] Vector3 buttonsPos;
Vector3 buttonsPosCache;
[SerializeField] TextMeshProUGUI buttonLanguage;
[SerializeField] GameObject disableButton;
[SerializeField] GameObject videoRectangle;
int cacheWidth, cacheHeight;
float videoWidth, videoHeight;
float videoWidthCache, videoHeightCache;
double videoTimeCache;
bool fullScreen;
float timerMouse;
public bool languageChange = false;
public string videoFileName;
public string videoFileNameEN;
public string videoFileNameDE;
//Start
private void Start()
{
playButton.image.sprite = Resources.LoadAll<Sprite>("icons")[25];
videoRectangle.SetActive(false);
videoHeight = fullScreenImage.gameObject.GetComponent<RectTransform>().sizeDelta.y;
videoWidth = fullScreenImage.gameObject.GetComponent<RectTransform>().sizeDelta.x;
buttonsPosCache = buttons.anchoredPosition;
}
//Update
private void Update()
{
if (video.isPlaying)
{
if (!video.isPrepared) return;
videoSlider.value = (float)NTime;
video.SetDirectAudioVolume(0, volumeSlider.value);
}
if (fullScreen)
{
if (Input.GetAxis("Mouse X") != 0 || Input.GetAxis("Mouse Y") != 0)
{
timerMouse = 0;
buttons.gameObject.SetActive(true);
}
else
{
timerMouse += Time.deltaTime;
if (timerMouse > 3)
{
timerMouse = 3;
buttons.gameObject.SetActive(false);
}
}
}
}
public ulong Duration
{
get { return (ulong)(video.frameCount / video.frameRate); }
}
public double VideoTime
{
get { return video.time; }
}
public double NTime
{
get { return VideoTime / Duration; }
}
//Prepare Method
public void LoadVideo(string source)
{
video.url = System.IO.Path.Combine(Application.streamingAssetsPath, source);
video.Prepare();
}
//Methods for Buttons
public void PlayVideo()
{
//if (!IsPrepared && IsPlaying) return ;
video.Play();
}
public void PauseVideo()
{
if (!video.isPlaying) return;
video.Pause();
}
public void SeekSlider()
{
video.time = (videoSlider.value * Duration);
}
public void PauseResume()
{
//if (!IsPrepared) return ;
videoRectangle.SetActive(true);
if (video.isPlaying)
{
playButton.image.sprite = Resources.LoadAll<Sprite>("icons")[25];
PauseVideo();
}
else if (!video.isPlaying)
{
playButton.image.sprite = Resources.LoadAll<Sprite>("icons")[24];
PlayVideo();
}
}
public void FullScreen()
{
if (!fullScreen)
{
disableButton.SetActive(false);
fullScreenImage.gameObject.GetComponent<RectTransform>().sizeDelta = new Vector2(1920, 1920);
buttons.anchoredPosition = buttonsPos;
fullScreen = true;
}
else
{
disableButton.SetActive(true);
fullScreenImage.gameObject.GetComponent<RectTransform>().sizeDelta = new Vector2(videoWidth, videoHeight);
buttons.anchoredPosition = buttonsPosCache;
fullScreen = false;
}
}
public void ChangeVideoLanguage()
{
if (!languageChange)
{
buttonLanguage.text = "EN";
videoFileName = videoFileNameDE;
video.Stop();
playButton.image.sprite = Resources.LoadAll<Sprite>("icons")[25];
LoadVideo(videoFileName);
languageChange = true;
}
else
{
buttonLanguage.text = "DE";
videoFileName = videoFileNameEN;
video.Stop();
playButton.image.sprite = Resources.LoadAll<Sprite>("icons")[25];
LoadVideo(videoFileName);
languageChange = false;
}
}
}