The only way we could have any idea about what is going on is if you gave us project details. Most likely culprits are incompatible footage or missing third-party effects. There is nothing inherently difficult about opening projects from the same or later versions of AE on a different operating system.
Hey Rick, thanks for responding!!
What kind of project details would you like? I have 10 different project files (everything collected & organized) from a show I worked on last year. Everything was created on AE 15.0 on a Windows computer. I'm just trying to open any of the project files on any of my 3 Mac computers, but not one computer, or version of AE will open these files. It takes 2-3 hours to attempt even opening the project, and then IF it opens, it completely freeze AE. It's like my machines are having a hard time reading the Windows files or something. This is the first time I've ever encountered this problem!
I forgot to add that none of the plugins or effects are missing from any of my machines from the one that they were created on. All the footage is there, all the effects are installed, everything is good.
But are the precise same versions of the effects (I presume they're 3rd party plugins) on your destination machine?
Are the projects and corresponding source footage on an external drive?
Copy the AEP to the Desktop, unmount the drive and then open the project with all the source footage missing. Do a Save As back to the Desktop. Reconnect the drive, copy the new AEP back and try opening it (with your fingers crossed).
An alternative is to open a new AEP, import the problem AEP into it with the source footage missing and then relink the source footage manually. Of course, that’ll take awhile.
Thank you for responses. Nothing is working. I don't know what the problem is, or how to fix it. It's ONLY these files from this show. This is the frozen screen I've been looking at for an hour.
Warren, can I email you one of these files (without the footage) and see if you're able to open it and convert it to a new file I could try and open?