Command block

Hello fellow coders (:

I started to find commandblocks more intresting these days because there are alot more commands but there is a little bit of a problem with my minecraft.

Recently in 14wb02b the @e command got added but when I start one of the snapshots on my computer the @e isn't even in the game. (I tried them all)

So now I can do particle commands but no @e and I really need it .

There is no error message neitger @e under the @p @a or @r only @p @a @r in the commandblock.......................

so what is the problem I would like to know did I mess up my game or something????