Some of you may have noticed that BLG "disappears" after an update. Well, that's because it does. Somehow between RC1 and 1.0, the updater was borked and instead of downloading updates, it downloads an error message and saves it as System_BlocklandGlass.zip, which then means the add-on doesn't load because the zip is gone. Because of the fact that I've gotten around, oh, zero bug reports, I had no clue until I asked someone why the database still shows them running 1.0, and they responded that after the update, the console had some error about it not being a valid zip. So, everyone who downloaded before 1.1.1 needs to re-download. Same link as in the OP.