Doing "/kill @e[Type={whatever}]" on servers (at least) yields "Error: Player Not Found"

Doing

/kill @e[Type={whatever}]

on servers (at least) yields "Error: Player Not Found". It's very irritating because I don't know how to remove some random armour stands that have been placed around my server spawn by another admin. The only way I know how it to do "/kill @e" but that would destroy a lot of other useful armour stands and entities so it isn't an option.