This is a recent issue for me that when I am trying to fix the names of files on my external it’ll say it isn’t responding and then remain frozen. Also the same issue happens when I try to delete things. I thought it may be my laptop at first but I’m pretty sure it isn’t because I can do those tasks on the laptop with no issue. Every time I get the not responding warning, I have to unplug the hard drive. I also have to unplug it without ejecting because I when I try to “end task” it won’t let me. When I plug it back in, the issue happens again. Please help me out! 
Are you able to retrieve the files? If so, go ahead and retrieve them so you can format the unit and start over. Also, you can test the unit with WD’s DLG tool for defects. Below I will paste some links for more information.
Hope it helps!
