java.lang.NoSuchMethodError: org.bukkit.inventory.Inventory.getStorageContents()[Lorg/bukkit/inventory/ItemStack;

[L4BORG]

[23:53:11] [Server thread/WARN]: [Auctions] Task #121682 for Auctions v2.5.0-SNAPSHOT generated an exception
java.lang.NoSuchMethodError: org.bukkit.inventory.Inventory.getStorageContents()[Lorg/bukkit/inventory/ItemStack;
    at com.sainttx.auctions.util.AuctionUtil.getFreeSlots(AuctionUtil.java:48) ~[?:?]
    at com.sainttx.auctions.api.reward.ItemReward.giveItem(ItemReward.java:68) ~[?:?]
    at com.sainttx.auctions.structure.DefaultAuction.end(DefaultAuction.java:194) ~[?:?]
    at com.sainttx.auctions.structure.AbstractAuction$AuctionTimer.run(AbstractAuction.java:215) ~[?:?]
    at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:59) ~[patched.jar:git-TacoSpigot-"65fd35f"]
    at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:349) [patched.jar:git-TacoSpigot-"65fd35f"]
    at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:783) [patched.jar:git-TacoSpigot-"65fd35f"]
    at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:378) [patched.jar:git-TacoSpigot-"65fd35f"]
    at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:713) [patched.jar:git-TacoSpigot-"65fd35f"]
    at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:616) [patched.jar:git-TacoSpigot-"65fd35f"]
    at java.lang.Thread.run(Thread.java:745) [?:1.8.0_102]

Latest auc, latest 1.8.8 paperspigot.