Right click the Blockland folder and click "Get Info" .
Then in the new window, under "Sharing & Permissions" click the padlock if it is locked. If it is open then skip next line.
When you click the lock it will ask you for your password, enter it in.
Then, click "Read Only" then choose "Read & Write"
???
Profit!!!1!1!111!1!1!1!!!1!!1one