PremiumVanish by default blocks chat while you are in vanish unless you put a / after your message, but if you do that, the / is not supposed to be sent with the message but the PowerRanks chat formats still show it.

Added workaround in commit.
52a846c

In general I do not add support for any premium plugins and a proper fix won't be implemented.
But this fix should work, just untested.