Economy ++ Signshop does not work what to do?

First of all, hello, I have a 1.8 Minecraft Server (Bukkit / Spigot) and use Economy Plugin as Economy ++ and I'm very satisfied, but the Signshop does not work (both buy and sell) so the sign changes

(1st line = [Economy ++]

2nd line buy

3rd line 1 (ID for stone)

4th line 2 (price per piece)

Hi

try the plugin Essentials this has a sign shop buy and sell and an economy plugin at the same time