I DID NOT FIND THIS OUT BUT STILL READ
I found out how to bypass the error (won't always work though, so please don't be all so hating)
This is Windows 7, should be the same process for other computers (definitely not Mac)
Find 'Computer' (should be on the desktop, start menu etc)
Go into the 'Local Disk', then find 'Program Files (x86).
Find a folder named 'Blockland', open it up then run the launcher and you should be good to go!
I hope this helps everyones problem.
Take Note: This doesn't fix the problem, it only bypasses.