I have never had problems uploading photos, suddenly I get this message on my mac:
"The following files were not imported because they could not be read. (1)
I can upload the photos to mac's "Photos" so I believe this is a Lightroom issue and not the disk.
I have Lightroom 4.
Thank you for your help.
Either you have accidentally changed the Destination folder, or the Destination folder does not have write permission.
So, if you accidentally changed the Destination folder, change it back. If that's not it, in your operating system make sure that this folder has write permission.