delete these files:
SimpleTunnelLarge.txt
SimpleTunnelSmall.txt
Add the skybox files to your map folder, since its not part of the blockland default, and fix the path in your .mis file.
Either include the detail image in the map folder
-or-
fix the spelling so it uses whats included with blockland's default files.
You should be able to brows the files Blockland\data to see whats actually there, and then fix things.
Then regenerate the zip file without the mac specific stuff (.DS_Store, _macosx). how you go about this, I dont know.