In the import dialog ensure that the destination panel is expanded and that the folder you are importing into is shown in the file path top right.
The folder should also have read & write permissions. Press Cmd+i to bring up the info dialog and click the lock icon if permissions need changing.
99jon has you pointed in the right direction.
"Cannot be read" means "cannot be read from the hard drive". This means the writing to the hard drive failed during the copy phase. 99% of the time this is a permissions problem on the destination folder or its parent.
In the import dialog, make sure the destination panel is open and that the folder you want is correct.
Using Finder, make sure the destination folder and its parent have READ and WRITE access.