Red sand trade shops

I'm sorry if this has been asked before, but I couldn't find it through the forum's search option.
I'll keep this short and simple, red sand is a legal trade item, however, when I try to make a trade shop using a sign it tells me red sand is an illegal item and breaks the sign.
I was wondering if this is in fact an intentional feature, or an accidental bug. If this is supposed to happen, then I understand that. If not, then please tell me what I may be doing wrong.

 

You have to manually trade red sand on classic, it is legal to trade yes.
big fat cough if you don't want to manually trade it, join the new server

 

Yeah you have to manually trade it who knows make a suggestion on it has your question been answered would you liked this closed

 

Question has been answered, thread may be closed.

 

Thank you for your thread on a recent issue. The issue has been resolved.
This thread has been moved to the Help Archives.