I have been using my WD My Passport for Mac for a few years now. It has been great up until recently. Now, when I try to access files from MacBook A on MacBook B, I get denied with a pretty red circle with a line through it saying that I do not have permission to access the files. When I go back to MacBook A, I can then access those files again. I have tried playing with the permissions on the preferences, but they show that I have ability to “Read & Write”. Help! Please!