What version of Premiere Elements. What Mac operating system? Is the issue with the Premiere Elements Editor and the Elements Organizer or both?
1. Is this a "it worked before or not now" issue or "it never worked before" issue?
2. Does the problem exist with and without antivirus and firewalls disabled?
3. Do you have the latest version of QuickTime installed on the computer with Premiere Elements, and are you running the programs as administrator?
4. Is your video card/graphics card driver version up to date according to the web site of the manufacturer of the card or the manufacturer of the computer?
5. Depending on your reply to "1", does your computer system meet the published System Requirements.
System requirements | Adobe Premiere Elements Are you working for a company or school network where permissions could be an issue?
The problem that you present is a generalized one that needs definition with details.
What did troubleshooting did Apple Support go through with you?
Let us start here and then decide what next based on the details in your reply.