It is a bug and Oasis is already aware of it.

Yes, under the bug and report section there is a discussion to report the server affected by this bug, if your server has not been listed yet, feel free to report it there. You will help the developer fixing the issue.

It's not removed since last week they said weekend missions will be in rotation since there are 4 missions now : https://forum-narutoen.oasgames.com/page/show-post-23303-5.html post 93＃

Thats odd. I completed Lucky Throw, Chase Mission, and Team Instance from 0730 - 0830. When the server hit 0900, the puzzle opened up. Maybe there's a time delay.

I'm pretty sure it is NOT a bug:

Yay for a new feature what may make it so that some players will not see chase missions for few weeks.

As stated in another thread under bug section, it seems that weekend events are in rotation cycle, so every week there will be 3 events and one missing (since there are 4 different weekend events).

Lets hope chase mission will be back next week ^_^

Essentially it's yet another slap in the face for everyone. We got the "wonderful" addition of a new rng dice event which means now a rotation is required because hey, can't have four weekend missions, right? How about we just say thanks but no thanks, you can keep your dice, and we'll go back to the way things were. I highly doubt anyone would consider it any great loss.

Hi guys! I know there has been some confusion between whether it is a bug or a rotation between the four available events. As of now, I have heard that it is actually a rotation between the four events, but I am trying to find out more and figure out if it is a permanent change.

I will either update this post or *y an official post when I hear back from them!

~Jib