Hi, I have a friend who I can't get to post here, but he needs help, so I am posting for him.
In short, my friends Blockland key does not grant him full version. What happens is, he enters the key, and then the "Full Version Unlocked!" window appears. Shortly after (0-4 seconds) the game reverts back to demo, and the bar on the bottom of the screen says "Authentication FAILED: Invalid Key" Clicking the retry button next to this changes the text to "Authentication FAILED: ID does not exist." ( <- not sure if that's exactly how it put it but it says something about an ID not existing. I can't really give you much more information of the top of my head.
He has tried reinstalling.
Can anyone help?