What version are you using? The most up to date version is Carbonite 5.4.2 Alpha 5. It's available on
WoWInterface.com and
CurseForge.com.
If you use the Curse Client to download and install addons, you can use that by finding the Carbonite entry in the list of installed addons, right clicking, and choosing "Install Type" in the menu. Then, in the fly out menu, choose "Alpha" and you should be good to go.
WoWInterface has an addon installer, also. It's called
Minion. Be careful, though. It's in Beta and it can have some glitches.