HolographicDisplays Floating Items

So, I'm making a prison server, and I have this problem... I can't make floating items with HolographicDisplays.
Here's what happening.. please help. Remember subtitles, or the video won't make any sense!! Also sorry for my bad english.

 

@Fliiint Try to use this:

Code:

/hd create test ICON:diamond

Instead of this:

Code:

/hd create test ICON: diamond

Difference: No space between 'ICON:' and 'diamond'

 

Same happens..

 

@Fliiint I see, i've never tried it myself but i just looked it up and it showed the command without the space so i thought i would let you know. Anyway i have no idea why it doesn't work, do you have anything in the console on startup or when you execute the command?