Why is it that if I go to install an add-on from User Preferences > Add-ons > Install from File... and choose a *.ZIP, some add-ons will install, while others will return me to the User Preferences with nothing having happened (as far as I can tell)?
Is there a specific file structure required in the .ZIP? I get many add-ons from GitHub, using the Download Zip button, and even there installation of the actual Zip file only works some of the time.

.zipfile is extracted into the add-ons folder (as it does in the source code) and the__init__.pyfile will get picked up by Blender. The system has been this way since Blender2.6according togit blame. I structured my add-on like the last one and it works fine... – Cobertos Sep 13 '18 at 02:24