It turns out that the placeholder of FabledSkyblock (%fabledskyblock_island_level%) which is provided by PlaceholderAPI, returns a string with some color codes. So this means it can not work with TheBestRanks because this plugin is only able to use the placeholders that returns an integer or double.
BUG FIX:
Now we've added some local support for FabledSkyblock in our plugin. Now you are able to create ranks using fabledskyblock island levels again.
How? Just add "fabledskyblock-island-level" section to the "requirements" section. For example:
Code (Text):
'1':
prefix: '&7[&aReal Man&7]'
requirements:
fabledskyblock-island-level:
required: 25
gui-message: '&aIsland Level&7: &e%your%&7/&b%required%'
deny-message: '&7Your island level is not enough! Your island must be %required% level! But you are %your% yet!'