I am not sure, I understand what the problem is exactly:
Files are visible when asking to import but the thumbs are not seen on Aperture window.
Do you mean, you are seeing the jpegs in the "Import Panel", but after importing you do not see them in Aperture's Browser? Or which Aperture Window are you referring to?
What library item have you selected in Aperture's Inspector, when you are looking for the imported images? Are all search filters in the Browser cleared?
, I see only the file, where these photos are, not the photo names or thumbs inside the file (Aperture import path).
You mean in the Aperture Import panel the folder, where the jpegs should be, is empty?
Then you may have excluded jpegs from import in your "Import Settings".
Check the above settings in the "Import Settings" options in the "Import Window". I.e-make sure the Raw+Jpeg Pairs option is set to "Both", even if you do not import raws.
After reassembled all the programs to a new hard drive in Mac Pro
Is this new Harddrive your system volume? And are the jpegs you wat to import located on this drive? Or are the on another external volume? If yes, how is this volume formatted?
Have you checked the permissions and ownership of the jpegs?
Photos are in different hard drive and the problem is that some of the photos I can import but some not (from that same hard drive).
All are my own photos and earlier when System HD was the old one, there were no problems.
I have downloaded now 5000 jpg photos and can do more, but exluded there "problem files".
Have you checked the permissions on that volume? Is it formatted MacOS X Extended? if not, I'd recommend to reformat the drive as MacOS X extended using Disk Utility, otherwise you may have problems with certain filenames. And is your new drive directly connected, or is it a network volume?
To check for permission problems select the drive in the FInder and use the command "File > Get Info". Disclose the "Sharing & Permissions" brick.
To avoid permissions problems with your older image files I'd suggest to set the "Ignore ownership on this volume" flag, like below.
After searching the reason for this trouble after all these advices, I finally found it. The reason is here. When you have a copy from certain photo-file already in the Aperture, the browser does not show the content of the other file from the same photos, you want to look. The "No duplicates" must be on.
Thank you for all the advices. They were great support.
the browser does not show the content of the other file from the same photos, you want to look.
That explains it! Aperture does everything to prevent you from filling your library with duplicates. But why did you want to import jpegs already in the library? You know, that you can always create a second version of a photo (Photo > New version from Original/Duplicate version) to have a second copy without needing much additional disk space.