Lockout instance what is this thing?

[Chinesehero]

just now I play and I can get in alone
But it already reset and not from the boss before.
Next time dont make this kind of event. Wasting time

[Hargrim]

Next time dont make this kind of event. Wasting time

We will do what we want, thanks for valuable feedback tho.

[Dackle]

Blah, blah, blah... ...screw it let's queue.

[Grunbag]

You get a lockout for the boss you killed , or if you leaved your group and they replace you with someone else to finish your instance .