Hewwo there! I'm sure when I say 'Mob-Arena', it brings back fond memories of dodging zombies, attacking skeletons, all while hanging onto your last heart. I was gone for about 2 years; due to a technical problem with my computer, and when I came back, Mob Arena was gone! I miss being able to play with friends while competing to win nether stars and your own head. If it's not too much trouble, I would at least like it to be open during October/Halloween. If the reason it was closed was that too many people were getting rich/ winning a lot of the prizes too often or something like that, the rates of winning or the mobs could get more difficult. (Higher stakes/ Lower chance of winning). But if it was just closed without really providing much of a reason, I guess I'm asking for it to be open again at least once a year.
It was closed due to a duplication glitch and currently they are rebuilding the mob arena due to it having a lot of glitches and bugs(Such as a broken health glitch). Currently they have said they are working on upgrading the mob arena but they don't know when they'll be finished. The mob arena also caused large amounts of lag so the upgrade will probably help, although it really doesn't seem to be coming out any time soon. (Basically they're trying to upgrading the mob arena as the transfer to 1.8 to 1.12.2 caused a lot of bugs and some lag.) Also I think a competition can be arranged if everyone goes to the old skyblock (Have to be on 1.8) because the mob arena still works there. (Honestly I'm not sure how far they are to completing the new mob arena as they don't really talk about it much and they have had some staff retire, but I'm pretty sure it's not coming any time soon.)