Migrated from: https://dev.bukkit.org/projects/shopkeepers/issues/532

Originally posted by Glorlyg (Aug 17, 2017):

Hi!
 
We got this error message from server console. You can see it in the spoiler. We could see this error when we wanted to buy or sell enchanted items. How can we handel this error?
 
We use Shopkeeper v1.31.
Server version: CraftBukkit version git-Spigot-1.7.9-R0.2-204-g534549b (MC: 1.7.10) (Implementing API version 1.7.10-R0.1-SNAPSHOT)
We are a Hungarian 1.7.10 SMP server - YodaCraft Nostalgia (go.yodacraft.hu) .
 
Thanks for your fantastic work!
We are looking forward for your response. Thanks in advance!
Spoiler (click to show)
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:514) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:499) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.PlayerConnection.a(PlayerConnection.java:1477) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.PacketPlayInWindowClick.a(PacketPlayInWindowClick.java:15) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.PacketPlayInWindowClick.handle(PacketPlayInWindowClick.java:65) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:186) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.ServerConnection.c(ServerConnection.java:81) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:734) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:289) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:584) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:490) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
Caused by: java.lang.NoClassDefFoundError: org/bukkit/inventory/meta/BannerMeta
at com.nisovin.shopkeepers.Utils.areSimilarReasoned(Utils.java:369) ~[?:?]
at com.nisovin.shopkeepers.Utils.areSimilar(Utils.java:125) ~[?:?]
at com.nisovin.shopkeepers.ui.defaults.TradingHandler.itemEqualsAtLeast(TradingHandler.java:191) ~[?:?]
at com.nisovin.shopkeepers.ui.defaults.TradingHandler.onInventoryClick(TradingHandler.java:114) ~[?:?]
at com.nisovin.shopkeepers.ui.UIListener.onInventoryClick(UIListener.java:52) ~[?:?]
at sun.reflect.GeneratedMethodAccessor518.invoke(Unknown Source) ~[?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_144]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_144]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:298) ~[minecraft.jar:git-Spigot-1.7.9-R0.2-204-g534549b]
... 13 more

Originally commented by blablubbabc (Aug 22, 2017):

v1.31 doesn't seem to actually be compatible with 1.7.x (even though it was intended to be). This was fixed in v1.40. However, you might be fine to even try v1.68 downwards. Make sure to read the changelogs in between, in case there were any updating notes. Also make sure to backup all plugin data before attempting the update.
 
Note though, that those old versions have several bugs which have only been fixed in newer versions of shopkeepers. So you might also want to read the changelogs of the newer versions to know about those potential issues. I have no plans to support older versions of minecraft, so if you run into any issues with those old plugin versions, you are on your own there..

Originally closed by blablubbabc (Aug 22, 2017)

Originally commented by Glorlyg (Aug 23, 2017):

Thank you for your effort!