Deleting the cache.db file didn't work, however I can click the links to download blobs.
Does the game work in a new default installation? Try making a new directory like "Desktop/blocklandtest/", and then, since I see that you use Windows, open command prompt, CD to the directory your launcher is located in, and type
start BlocklandLauncher.exe -profilePath [newdirectory]
Your BlocklandLauncher.exe might be in C:/Blockland/ or C:/Program Files (x86)/Blockland/ or maybe your Documents/Blockland folder.