I'm using Lightroom CC 2015.7 Camera Raw 9.7. Macbook Pro with Yosemite 10.10.5.
I've tried to import to different folders and using different catalogs. I've also checked the folder permissions to make sure they were read/write (and they were set up correctly).
Then your user name does not have Write permissions for that folder. Change folder to one your user name has Write access to or change the permissions on that folder and the folders above that folder.
even if the Sub-Folder you are pointing LR to has Read + Write permissions if the top level folder doesn't have the proper permissions then LR can't write to it. Check the Top Level folder for proper permissions and change it as needed.