Notes Will Not Save

Notes Will Not Save

When entering notes within Leads or Contacts, the information will disappear, and not save. (See Image Below)

A blank box appears when I click the save button. 

I've tried multiple browsers, clearing my cache, deleting my cookies, logging out and back in, and attempting under different users.

This is frustrating. I have to double the amount of work I do since the notes will not save. Please advise.