Tips to open M21 file

Can't open the M21 file? You are not the only one. Thousands of users face similar problems every day. Below you will find tips on how to open M21 files as well as a list of programs that support M21 files.

M21 file extension

File Name MPEG-21 Format
File Category Video Files

The M21 file is supported on 2 operating systems. Depending on your operating system, you may need different software to handle the M21 files. Below is a summary of the number of programs that support and open the M21 file on each system platform.

Operating systems
  • 1
  • 1
  • 0
  • 0
  • 0
  • 0

What is M21 file?

The file with the extension M21 is the Video Files file type. Additionally, the Video Files category contains 546 of other files. MPEG-21 Format is most often found on 2 operating systems. The file will work on Mac OS, Windows systems, unfortunately not on others. The main program that supports this format is QuickTime Player. This was created by Apple, Inc.. This file type can also be opened by 1 other programs.

How to open M21 file?

The most common problem when using MPEG-21 Format is that a specific M21 is not associated with the program. Thus, when you open M21, the program selection wizard or some other program starts. How to solve such a problem?

The first thing you should do is just "doubleclick" on the M21 file icon you want to open. If the operating system has an appropriate application to support it and there is also an association between the file and the program, the file should be opened.

Step 1. Install QuickTime Player

In this case, you should first verify that the QuickTime Player application is installed on the computer. To do this, enter the name QuickTime Player into the system search engine. If we do not have this program, it is worth installing it, as it will help you automatically associate the file M21 with QuickTime Player. Later in this article you will find a list of programs that can open M21 files.

Programs to open M21 file

Remember to download programs supporting M21 files only from verified and safe sources. We suggest using the websites of software developers.

Step 2. Create association of QuickTime Player with M21 files

If, despite the installed application, the M21 file does not start in the QuickTime Player application, you must create a file association. This option is available from the level of Properties of a specific file available in the context menu. The displayed window will contain information about the program that supports this type of file. Using the "Change" button we can set the program to handle this type. The program should be visible in the window, otherwise it should be selected manually using the "Browse" button and the program installation directory should be indicated. However, it is important to check the "Always use the selected program ..." box, this will allow you to permanently associate the M21 file with the QuickTime Player application.

Step 3. Update QuickTime Player to the latest version

The fault may also lie with the QuickTime Player program, it is possible that MPEG-21 Format requires a newer version of the program. This can be done using the application (if it provides such options) or from the Apple, Inc. website and install the latest version.

Step 4. Check for the following problems with the M21 file

Of course, it may happen that despite the above steps, the file still does not work. File problems can be divided into the following:

Very often, the file may be size 0 or incomplete. This is most often caused by a problem while downloading the M21 file. Downloading the file again should fix the problem.
The most common cause here is computer viruses. Perform a virus scan using available and up-to-date anti-virus software. Some antivirus vendors also provide free online scanners. The scan should cover the entire computer, not only the M21 file that we want to open. As a result of the scan, sometimes it is not possible to recover M21 files, which are deleted if there is a backup of this file, then after restoring it, it must also be scanned.
This can happen especially when the program is dynamically developed and the structure of the M21 files changes over time. On their websites, developers usually offer free solutions to such problems, e.g. in the form of a conversion program or an older version of the program.
There can be many reasons for this. Depending on the type of file, it is necessary to repair it accordingly. Sometimes the program itself has options to repair the most popular M21 file corruption. The easiest way is to restore the file from a backup, if there is one, or contact N/A
The program can also signal the fact of encryption. The encrypted M21 files cannot be played on other computers than the one on which they were encrypted, they must be decrypted before using on another device.
The operating system protects files in some locations (e.g. the root of the system partition) against unauthorized access. The problem is only writing to the file, not reading it. Copying the M21 file to another location will fix the problem.
This problem usually affects more complex files. In this case, the M21 file is blocked by the first application to open it. Running programs (including those in the background) should be verified. Sometimes it is necessary to wait a while before referencing the M21 file again. Some anti-virus or backup software may occupy the M21 file for a certain period of time. If the problem persists, restart the machine.