Good evening my dear anons. Due to a game update the Beastaber lobby is once again postponed until a new version of the multiplayer mod is released.

This update will break all of your current mods but it's not to hard to get them working again and you can play custom beatmaps at least. I would refer you to the op but looks like it's still vandalized. 
What you will need to do is run the game once to update then download the new mod assistant version from here:
https://github.com/Assistant/ModAssistant/releases
And then just install mods as normal. Fairly straightforward but there's a lot currently missing. I would rerun it over the next week as more mods will update to the newer version and will appear in the list.
There's no telling how long it will be before an update. It's been several months and the original mod dev has still not released an official update, so the patch will likely come from some other fork. I'll post an update when I know more.