I am running a PaperSpigot 1.10.2 server and using the latest release of this plugin. But while enabling this plugin, it crashed. Here is the terminal output.

[11:23:52 ERROR]: Error occurred while enabling ExtraHardMode v3.12.1 (Is it up to date?)
java.lang.AbstractMethodError: Method org/sqlite/Stmt.isClosed()Z is abstract
        at org.sqlite.Stmt.isClosed(Stmt.java) ~[patched_1.10.2.jar:git-Paper-916.2]
        at com.extrahardmode.module.MsgPersistModule.initializeTables(MsgPersistModule.java:230) ~[?:?]
        at com.extrahardmode.module.MsgPersistModule.starting(MsgPersistModule.java:73) ~[?:?]
        at com.extrahardmode.ExtraHardMode.registerModule(ExtraHardMode.java:241) ~[?:?]
        at com.extrahardmode.ExtraHardMode.onEnable(ExtraHardMode.java:85) ~[?:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:292) ~[patched_1.10.2.jar:git-Paper-916.2]
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:316) [patched_1.10.2.jar:git-Paper-916.2]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:407) [patched_1.10.2.jar:git-Paper-916.2]
        at org.bukkit.craftbukkit.v1_10_R1.CraftServer.enablePlugin(CraftServer.java:375) [patched_1.10.2.jar:git-Paper-916.2]
        at org.bukkit.craftbukkit.v1_10_R1.CraftServer.enablePlugins(CraftServer.java:325) [patched_1.10.2.jar:git-Paper-916.2]
        at net.minecraft.server.v1_10_R1.MinecraftServer.t(MinecraftServer.java:424) [patched_1.10.2.jar:git-Paper-916.2]
        at net.minecraft.server.v1_10_R1.MinecraftServer.l(MinecraftServer.java:389) [patched_1.10.2.jar:git-Paper-916.2]
        at net.minecraft.server.v1_10_R1.MinecraftServer.a(MinecraftServer.java:329) [patched_1.10.2.jar:git-Paper-916.2]
        at net.minecraft.server.v1_10_R1.DedicatedServer.init(DedicatedServer.java:275) [patched_1.10.2.jar:git-Paper-916.2]
        at net.minecraft.server.v1_10_R1.MinecraftServer.run(MinecraftServer.java:590) [patched_1.10.2.jar:git-Paper-916.2]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_131]
[11:23:52 INFO]: [ExtraHardMode] Disabling ExtraHardMode v3.12.1

I tried to google this error, but there was no related result. Could any suggestion be given? Thanks in advance.

You need to update paper.

Or use an older version of EHM for MC 1.10.2 if you insist on using outdated, exploitable server versions.