---
title: "Troubleshoot common issues"
slug: "vpe-troubleshoot-common"
updated: 2026-09-17T09:22:39Z
published: 2026-09-17T09:22:39Z
canonical: "guide.ncloud-docs.com/vpe-troubleshoot-common"
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://guide.ncloud-docs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshoot common issues

Available in Classic and VPC

You might run into the following problems when using Video Player Enhancement. Find out causes and possible solutions.

## "The license is invalid." error message

"The license is invalid." error message is displayed when playing a video, and the video does not play. Errors E0005 is displayed.

#### Cause

To validate the domain, you must enter the site domain address in the domain settings. If the domain doesn’t match, a license error will be triggered.

#### Solution

Check to make sure the domain matches the one registered.

## License error when registering domain

If the site domain is registered in the form *.a.com, a player license error occurs.

#### Cause

Currently, wildcard formats are not supported for site domain registration.

#### Solution

Since wildcard formats are not supported, register all sites individually.

## Missing video control bar

The control bar does not appear on videos when viewed on mobile devices.

#### Cause

The control bar may not be displayed due to other elements in the HTML where the player is installed or CSS affecting the player.

#### Solution

Install only the player in the HTML to perform a test. If there is no issue, check for any conflicts with the CSS elements in the HTML.

## Missing fullscreen button

The **[Fullscreen]** button does not appear when viewed on mobile devices.

#### Cause

If the **[Fullscreen]** button is set to be disabled in the console, it will not appear.

#### Solution

To enable the **[Fullscreen]** button, follow these steps:

1. On the NAVER Cloud Platform Console, click **Menu** > **All Services** > **Media** > **Video Player Enhancement** > **Video Player Management** in order.
2. Click the **Options Settings** button.
3. In the **[Player UI]** tab, go to **Control Bar Button Settings** and enable **Fullscreen**.
4. Click the **[OK]** button.
  - For more information, see [Control Bar Button UI](/docs/en/vpe-example-ui#%EC%BB%A8%ED%8A%B8%EB%A1%A4%EB%B0%94%EB%B2%84%ED%8A%BCUI).

The steps to force set the option UI are as follows:

```
-uilet player = new ncplayer('video',{
new ncplayer('video1', {
  playlist: [
    {
      file: "{URL}",
      poster: "{path"",
    },
  ],
  autostart: false,
  controlBtn: { // controlBtn options are available only for paid users
      play: true, // Playback
      fullscreen: true, // Switch to full screen
      volume: true, // Volume control
      times: true, // Playback time
      pictureInPicture: true, // PIP
      setting: true, // Settings
  },
});
```

## iOS web browser error

- The token feature does not work on iOS web browsers.
- If you click the **[Fullscreen]** button in an iOS web browser, an error message is displayed: "TypeError: undefined is not an object (evaluating 'this.video_player.textTracks[t].mode="showing"')."

#### Cause

- This feature does not work on the iPhone simulator.
- This is an unsupported version.

#### Solution

- Use Player SDK version 1.1.2 or higher.
- Enable automatic updates (/ncplayer.js) and clear the cache.

              Note

              

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