Bug with Joint Task Reward

Dargogo

Hi,

I'm Dargoa, from Server 24.
And i want to report a missing reward at the end of the Joint Task event.
I cleared all tasks from the day. And unfortunately, the button from the right column (as you can see) was not highlighted. So, i could not have the ultimate reward from joint task.

How can you repair that?
Please, tell me what to do.

Thanks.