It won't break, it just may not work, it all depends on where you decided to install blockland.
Basically, wherever you installed blockland, let us call this (x)/Blockland, you will need to put the addons in the (x)/Blockland/Add-ons folder.
(x) could be C:/ D:/ F:/ C:/Programme Files D:/Games
or anything, just place the addons where you installed the game, in the add-on folder.