Cant summon Voidwalker

I just reached lvl 10 with my Warlock.
I completed the prequests, that should lead me to get my Voidwalker pet.
But the last quest seems to have a bug.
When i use the glyph, that is used to summon the voidwalker, on the summoning circle in Orggrimmar, nothing happens.
Itried repeatedly to summon the Voidwalker without any luck.
Retaking the quest doesnt work either.
And appearenty im not the only one, since there were multiple warlocks trying to summon.
Any help?

Looks like several people are complaining of summons not working in the bug tracker. So it may be a matter of time.

Yup reboot just fixed it for me.