Are you installing the "Carbonite 4.1 beta 1" release? You can't get it from Curse.com or WoWI. You have to download it from the
Carbonite 4.1 beta 1 download page. Follow the link, scroll to the bottom of the page and click on the "Carbonite 4.1 beta 1" link. Install as usual for a manual install.
In a case like this, there is no need to
delete any addons just to test something. Just
disable them in the "AddOns" window on the character selection screen.
One other thing: Before you reinstall Carbonite again, go to your
"\World of Warcraft\Interface\AddOns" folder and manually delete only the Carbonite folders (there are four). Then reinstall the "Carbonite 4.1 beta 1".
If you continue to have problems, it is possible that Carbonites "SavedVariables" have become corrupted, and need to be reset. If that is the case, go to your
"Path to your WoW folder\WTF\Account\ACCOUNT NAME\SavedVariables\" folder, and delete the
"Carbonite.lua" and
"Carbonite.lua.bak" files. Doing that
will reset your installation of Carbonite to default settings for
all of your characters on that account. This is because all of Carbonites settings are saved in those files. It's an "extreme" way to fix a problem, but, occasionally it has to be done.