Alright, so I've had blockand on mac for a few years now, but I've recently bought the Steam version, for Mac again.
So I've had the same issues as everybody at first; every time I started playing the game asked me to input my preferences about mouse, keyboard and internet connexion even thought I already did it. The game would also tell me that my preferences couldn't be saved. I did what everybody told me: I copied the config and client files from my original blockland folder (in documents) to my steam blockland folder (library/steam/steamapps/common/blockland) which fixed that problem, or so I thought.
Blockland now has my preferences. But It appears that the problem was not that the Steam version of Blockland on Mac can't save preferences, the problem is that the Steam version of Blockland on Mac can't save anything.
I start a singleplayer server, I build something, I save it, it reacts normally, but then it's not saved. It does not appear in the saves list when I click on the load button or save button. If I clear bricks or if I want to work on my construction later on, I can't load it. It's lost forever.
Also, if I enable add-ons, they won't appear in-game. And the next time I will go to the add-on selection menu, the add-ons I enabled earlier would have been disabled, as if I never enabled them in the first place.
So I can't save anything and I can't use add-ons. Wow. Those are seriously 2 game-breaking issues. Please, if someone has a solution or any explanation to why this problem is, please write it down in the comments. This is serious.
Also, please don't give me that "the solution is not to buy overpriced aluminium boxes" bullstuff. My Mac has no problems besides from Blockland and I have no intentions to replace it just for one game.