/testfor/kill/execute/say/etc @e doesn't work with a scorebord selector

Heyho,

weird problem regarding the testfor and other commands which uses scoreboard selectors:

i can't test for an entity with an scoreboard selector anymore:

/testfor @e[name=<entityname>,score_objective=<number>]
doesnt work.
/testfor @e[name=<entityname>]
works.

Besides the /testfor it also doesn't work for /kill, /execute, etc
It doesn't show any error message in the chat.