How are you accessing the MyCloud? One of the WD Apps, or File Manager. If File Manager, have you mapped the shares as network drives? If so, what credentials did you use?
It’s not unknown for MyCloud to have a ‘hiccup’ and corrupt the access rights. It might be worth logging in to the linux OS using SSH (or using WinSCP), and having a look at the share permissions. The discussion at this thread might help:
