Quick time player stopped working

Hello JDar555,

Thank you for using Apple Support Communities! I understand from the information you provided that Quicktime keeps quitting on your Mac; I'd like to help.

The following support article provides some troubleshooting steps to try for this behavior:

To help isolate potential causes for this behavior, I suggest seeing if this continues to be an issue when you restart your Mac in safe mode:

Use safe mode to isolate issues with your Mac 

If you're able to use Quicktime without issue, the next step would be to rule out incompatible login items:

If your Mac has a blue screen or other startup problems

Specifically, check out the section labeled “Test your login items”

Also, testing in another user account can help determine if this may be user or account related settings causing this issue. Here's how you can create a new user for testing:

How to test an issue in another user account on your Mac

Keep us posted with the results.

Best Regards.

JDar555 wrote

3. Apparently Quicktime works OK on another user account I created.

Try rebuilding the preference file:

From your Finder "Go" menu > "Go to folder" then copy & paste this file path:

~/Library/Preferences/com.apple.QuickTimePlayerX.plist

Click Go.

Delete the plist file and test.

JDar555,

Thanks for giving that a try. Based on the troubleshooting you have done, the next best step would be to contact Apple Support:

Contact Apple Support

Have a great day

Yoav,

This provides us with great information. Some of your login items may be the cause of this issue. While the following resource is for start up issues, it provides instructions on how to test login items.

If your Mac has a blue screen or other startup problems - Apple Support

Best Regards.