Aperture crashes on importing large folders

I'm trying Aperture 3.4.3 with the idea of using it as DAM software. But when I import an entire hard drive or many folders at once, it crashes or I get the spinning ball. The problem is also that after restarting it, the import process does not continue, so I need to start from scratch. But it's always the same.

Importing individual files is not an option for me. I need Aperture for importing thousands of pictures on different folders from different hard drives.

Any help appreciated