When I try to edit with a plugin or photoshop, I get the message ..."Aperture does not support the image format." What is wrong?

It's my understanding that I am importing the referenced files correctly. Is there another way I should import?

The Import dialogue has selections to import into storage other than the Aperture Library -- that would be the way to do in in Aperture. That is found in the Store Files In box.

But many recommend importing outside of Aperture from the memory card to first be sure they have been captured and saved before ever being in Aperture, and you can do that with drag and drop of the files from the mounted memory card. Then in Aperture you Import with instructions to leave the orginals where they are stored.

I use Managed Masters almost exclusively, so I import into the Library, but I have multiple drives in my Mac Pro, and have the library exclusively on its own volume which can easily be backed up in entirety. I do like to import video in folders on still another hard drive and volume, however.

Ernie