Candybar uses the debugstack() to figure out where the library is located to get a path to the default candybar texture.
The !!!Libraries generates a problem with that. !!!Libraries is an attempt imho to make a one big package of all libraries available easily thingy thing.
CandyBar doesn't like being in that path. Just download the CandyBar lib seperately and it'll work just fine. !!!Libraries seems to contain everything and the kitchensink. It really fixes nothing, just generates problems.
Solution: Download each lib seperately into its own lib folder. (That way you can also see mem usage per lib in warmup!) And ignore the externals.