I 've had MY Book for a couple of year and love it, 1T in size. Today as I was drag/drop file into My Book , cursor spin for a few minutes and then an error messege appeared saying it can not perform this function. Sorry I freaked and didn’t remeber the (-) number code it gave. Then a window opened that said this computer doesn’t recognize disc inserted… initialize, ignore, continue. To ignore or continue, it doesn’t mount. If I initialize, all the current info will be erased. My Book is supposed to be a back up! Why did it do this and is there a way around it? I have (2) compiuters and get the same reaction on them both. MacBook Pro and desktop is MacPro G5 Quad Core Intel Xeon. HELPPPPP!
The file system got corrupted
try going to first aid and see if able to repair the partition
you can use a recovery software to get the files if the repair does not work