I've just bought a new PC with Windows 7 installed and I've just reinstalled Blockland, but whenever I try to join a server (On the server page of the website, by pressing "join"), a window pops up saying Firefox doesn't know what to do with the link. I tried right-clicking on it as I would an unidentified program to specify that Blockland should open it but that didn't work.
On my old PC, which runs Windows XP, clicking "join" automatically brought up a Blockland window without this error so I don't know why it's happening now.