Could be any number of issues.
Could be your operating system. Or it could be your hardware configuration. Or a lack of free, clean, defragmented space on your C or main drive.
What operating system are you using? How fast is your processor and how much free, clean, defragmented space is on your C drive?
Have you ensured that you have the latest version of Quicktime, per the program's requirements?
It appearded that Elements 9 was not deleted when installing 10. Once I deleted the older version , I can now access the organizer. Thanks for getting me thinking! John
Adobe has always allowed one to keep previous versions of their programs on the computer. Upgrades do NOT overwrite, or delete the previous versions, and personally, that is the way that I want things to work. Going back some years, and for various reasons, I had one computer with Photoshop 4.0, 7.0 and CS installed. Each worked fine, side-by-side-by-side. In that installation, I had zero conflicts.
Glad that you got things sorted out.