When I click on the "black box" wich should be the picture I see the photo, however when i close the photo the thumbnail goes back to being a blackbox.
Try to recreate the thumbnails:
In Aperture select the photos in the browser, and use the command "Photos > Generate Thumnails" from the main menu bar.
If that does not help, try to repair your Aperture library with the Aperture Library First Aid tools, as described in Aperture 3: Troubleshooting Basics:
Press and hold the Option and Command keys as you start Aperture. The Aperture Library First Aid dialog will appear and offer the following three troubleshooting options:
- Repair Permissions. Some issues in Aperture may be caused by incorrect permissions for items in the library. To correct the permissions for your library, select the option to Repair Permissions then click the Repair button. You must authenticate with a user name and password for a user account with administrative access to perform this operation.
- Repair Database. Sometimes internal structures within the library may become damaged and cause unexpected behavior; you can use Repair Database to try to correct the issue. Select the option to Repair Database then click the Repair button.
- Rebuild Database. For more severe issues that can't be corrected with Repair Permissions or Repair Database, you can try Rebuild Database. It is strongly recommended that you have a complete backup of your Aperture library before performing this operation, either in the form of a recently updated vault, or a Time Machine backup. Select the option to Rebuild Database then click the Rebuild button in the Aperture Library First Aid dialog.
Before trying to rebuild, make sure you have a current backup of your library. Post back, if that does not bring the thumbnails back.