Hello,
I have imported from this card to the Mac before and had always formatted the card in the camera.
I found a solution to my problem. After 4 hours of “Restoring” I switched of the power of the camera. Afterwards I was able to copy the files in question from the card to the Mac (import via XDCAM Transfer didn´t work though.) I have then formatted the card and now it is working again.
Thanks for your help.
Michael