Problem: If your name has Ascii symbols (such as the ones in my name) and you are trying to register on the RTB forums, you are likely to get this error: "Authentication with Blockland Failed. Make sure your Blockland game is open!" even if your Blockland.exe IS open.
Solution: Remove your Asciis temporarily (or permanently!) and type in your information again. Make sure to enter the name you change it to.