I'd start by opening the project file on a different machine if possible to check if it's corrupted. If so, the trick of importing the project file into a new project has often worked over many versions of AE, including CS 5.5. You would then be able to create a new project file to open in CS 6.
Have you eliminated the possibility of corrupted media yet?
Well, cleaning Media Cache Database is not a crucial thing. If a project file is not corrupted, PrPro and AE successfully restore all necessary data on a project(s) first loading...
I could hardly help with reparing corrupted project file... Maybe some other worthies can... I'm able just check, if you upload your project somewhere (media files are not necessary)... And I hope you still have some backup copies from autosave...
Yes I have some bacup files, and orginal too.Im not sure the file is corrupted.AE just cannot load it.
Here is what happened:
1.I made a PPCS5.5 projetc, with 4 or 5 sequence.
2.I linked one sequence to an AE CS5.5 project. and made several effects on this sequence.
3.And I created a composition in this same AE project, and linked back to PP CS5.5 .This was a few months ago.
Now I made a clean install with CS6 (with same plugins like CS5.5.).And I opened the original PP project.CS6 created a new file from the orig.The project media loaded well except the linked AE composition.
Dave!Should I import the project into a new project like "Import file"?
Did you try to open this project on another machine?
Did you try to rename or move utilised media into another folder and then open the project?
Did you try to open any of backup copies of the project from autosave in AE CS6?
Did you try to open in AE CS6 any other AE CS5.5 projects?
Can you create and then reopen any project in AE CS6 at all?
Did you try to open this project on another machine? No, right now I dont have the chance.
Did you try to rename or move utilised media into another folder and then open the project? Not yet, I dont know which file, or folder?The whole project (AE & PP together) 400file around 100Gb.
Did you try to open any of backup copies of the project from autosave in AE CS6? Yes, I opened 3 autosaved version.None of them working.
Did you try to open in AE CS6 any other AE CS5.5 projects? Yes,I opened smaller project ,working.
Can you create and then reopen any project in AE CS6 at all? Yes, I made some test project, and reopened a few times.Working.
Thanks in advance!
Since you argue that PrPro project works fine, apart from loading dynamically linked comps, you should not bother about it at the moment. You need to isolate footages, images etc., which you exploit in your AE project only. If you don't remember which ones, you may e.g. create new 'Test Folder' in your hard drive and temporarily move all media files used in both PrPro and AE projects there.
Regard to testing your AE project on another machine, I already offered you to upload it somewhere (just a project file, no media files needed) so that someone from this Forum may try it.