Error: "You must select a topic"

1. I typed in a title
2. I typed in the body
3. I forgot to select a category
4. I clicked submit
5. I received the error "Enter a category"
6. I entered a cateogry
7. I clicked submit
9. I STILL received the error "Enter a category"

(ALSO: The back button doesn't seem to work very well when I'm wanting to navigate backwards from this form; it just keeps toggling between

https://premium.wpmudev.org/qanda/
https://premium.wpmudev.org/qanda/#
)