Coupon code creation not working

HI! I am trying to create a coupon for a customer and am getting this error message: "Whoops! Please use a Coupon Code that uses only letters and numbers. [JAB02-100]"
The coupon code does only have letters, the code i'm trying to create is simply "aloha"

Please help. Thank you!

Is there a space character before or after your coupon code?