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Summary: VLC Media Player, a popular multimedia tool, may display the “VLC does not support UNDF format” error due to incomplete downloads, missing codecs, or file corruption. Resolving it involves updating VLC, checking files, installing codecs, or converting corrupted files using a tool like Kernel Video Converter.

The VLC Media Player stands as the most widely embraced multimedia player, offering both a free and open-source platform. Its core purpose revolves around playing video and audio files. Furthermore, it boasts a range of exceptional features, such as video format conversion and the capability to rectify minor video file errors. However, users may encounter an error stating that VLC does not support the UNDF format when attempting to open an audio or video file. In this article, we will delve into the “VLC does not support UNDF format” error and explore methods to resolve this issue.

What is the UNDF format?

To begin with, UNDF does not constitute a file format; rather, it serves as an acronym for “undefined.” When you encounter the message “VLC does not support UNDF format,” it essentially signifies that the media player cannot properly identify or acknowledge the specific file format in question.

What causes a UNDF format error in VLC?

The UNDF format error in the VLC Media Player could occur due to the following reasons-

  1. The file that you are trying to play has not been downloaded completely.
  2. The audio or video file has not completed the transfer process.
  3. The codec which is required to play the file is not supported by the VLC media player.
  4. The video or audio files have been damaged or corrupted.
Methods to fix “VLC does not support UNDF format.”

The error “VLC does not support UNDF format” can be resolved by some simple fixes. Let us see them one by one:

  1. Update the VLC Media Player

    Updates typically entail enhancements aimed at rectifying bugs and minor glitches in the media player. In the context of an undefined format, the initial step should involve updating the VLC media player. This update can effectively address various issues and contribute to their resolution.
    You can download the latest version of the VLC media player through their official website.
    VLC media player

  2. Thoroughly check the media file

    Be sure to thoroughly examine the audio or video file. If you suspect that the file may have been incompletely downloaded or transferred, it is crucial to obtain a complete and proper download. Prevent any disruptions in power supply or internet connectivity during the download process to ensure a seamless and error-free experience.

  3. Install the necessary codecs

    Occasionally, VLC media player may not have the required codecs to support the audio or video format you’re attempting to play, resulting in the “VLC does not support UNDF format” message. To address this matter, it’s crucial to install all the necessary codecs, such as CCCP (Combined Community Codec Pack). CCCP is a comprehensive collection of codecs specifically designed for the Windows operating system.
    Follow these easy steps to activate all video or audio file formats codecs-

    • Install the CCCP that has all the audio and video file codecs.
    • Click on “LAV Video Settings” for a video file. For an audio file, click on “LAV Audio Settings.” LAV Video Settings
    • Go to “Formats.” Tick all the checkboxes and click on “OK.” Tick all the checkboxes
    • Now, the VLC media player identifies the undefined and then, you can play the video interruption free.

  4. Convert the files into a defined format

    One of the primary causes of the “VLC does not support UNDF format” error is file corruption within the video or audio files. It is essential to change them into a better file format. However, file conversion is a delicate process. For such critical tasks, it is advisable to utilize a professional tool like the Kernel Video Converter. This software employs an advanced approach to convert undefined files into well-defined formats, even allowing for conversions from 3GP to MP4 formats with precision.

    Follow these simple steps to convert the UNCF format-

    • Install the tool on your computer system.
    • Select the file using the plus sign “+.” Video Files Converter tool
    • The file gets added and listed. Now, click on “Next.” list of files
    • Select the video format in which you want to convert the current video file into.Select the video format to convert
    • Choose the destination to save the converted video file format. Choose the destination to save
    • The status of the format will change from “Processing” to “Success,” and it will get saved in the destination that you have selected.process done

This software possesses the ability to convert files of any size, free from limitations. It is compatible with all Windows operating systems and ensures that the quality of the file remains unaltered throughout the conversion process.


“UNDF format” is a term that essentially signifies an undefined file format. The error message “VLC does not support UNDF format” arises when VLC Media Player is incapable of identifying and playing the particular audio or video file format. This issue can manifest when the necessary codecs are absent in VLC, updates have not been applied, or when the file itself is corrupted. Nonetheless, there are methods to resolve this problem manually or by employing a video file converter.

Kernel Video Converter