I've switched from PC to Mac. I copy my projects of Premiere Elements (9) on my new Mac. After re-installing Adobe Premiere Elements 9, I can't open my projects. I recieve this message "The projetct is not compatible with the current version of Premier Elements" (in french "Le projet n'est pas compatible avec la version actuelle de Premiere Elements"). Why? There is a way to open my projects made in my old PC to my new Mac?
Classically you cannot open a project (project.prel file) created in Premiere Elements Windows in Premiere Elements installed on a Mac computer. And, the reverse is also true.
You can export your Premiere Elements Windows Timeline content to a .mov and .mp4 file, and then be expected to transfer that file to Premiere Elements Mac. Does that work for you? I have never heard of anyone finding an alternative.