By changing it, you can get it to operate correctly. Sometimes a Mac will have issues when reading your MP4 file’s code. The fix described here is specific to Mac computers, but it’s possible to change it on Windows-based systems as well. Quick Fix #3 – Change the CodecĪnother way to play an MP4 file when you encounter issues within Quicktime Player is to change the codec. When the settings window is open, select Updates, and then find Quicktime Player to make sure the current one gets updated to the latest version. Once you have the store window open, select the icon with three dots and select Settings. First, go to the Start screen and select the Microsoft Store. If you’re running Quicktime Player on a Windows-based computer you can easily update the program as well. Click on Quicktime Player and then select “update.” That will give you a list of all the installed applications and what updates they have available. If you’re running the program on a Mac, go into the App Store application and then click on the updates button. If you happen to be running an outdated version of Quicktime Player you can update it quite easily.

If not, continue reading for some other solutions. Then check to see if your MP4 file will open now. Once the program is closed, wait a few moments and open it back up. To restart your program, go to the Quit option from the drop-down menu in the top bar when Quicktime Player is open. The first way to do that is by restarting the program and/or computer and seeing if it resolves the issue. If you’re experiencing issues when opening an MP4 file, it’s a good idea to start with a small fix and work your way up from there. Quick Fix #1 – Restart the Program and/or Computer Unless the file is completely corrupted, you can typically get things fixed pretty quickly. There are also other errors that can occur with software updates. It could be as simple as a small, easy-to-fix glitch or as complicated as a completely corrupt file. There’s no one exact reason why an MP4 file might not open for you in Quicktime Player. Quick Fix #1 – Restart the Program and/or Computer.

Cant play mp4 on mac