I am on an iMac 27" Retina 5k System with 16 GB of RAM. I have a wired mouse and a wired keyboard plugged directly into the back of the computer into the USB slots. After an extended period of time (a few hours) of sleep, when I wake my computer up, the mouse is unresponsive. The keyboard works fine.
Why does this happen and how can I fix it?
It also says that one of my hard drives was not ejected correctly when all of them are still mounted and work fine. Why does this happen and how can it be fixed?