No delete button for scoreboard element

[T S]

I have 3 scoreboards and it wont let me press delete on the scoreboard element but there is a delete button for other elements?
http://prntscr.com/twwdzq

[ChocoPie_isme]

you can delete it in hud.json

[infAura]

@T-S
.t noscoreboard

[T S]

thaaaaanks