Crash when Summoning Some Blocks

So , i dont mean that when summoning cause a crash , when you summon
/summon FallingSand ~ ~ ~

{Time:1,TileID:17,Data:12,DropItem:0}

It does a Log.
But when i wrote TileID:18 instead of 17 it cause a crash.
Ill report it here.
Not sure if its a bug , or its impossible to summon this.
If is impossible : Tell me to delete the Content.
If its a bug : Just ask me for Development console , crash reports , etc.