console warn or error (not causes any problem on server)

[comonier]

[20:15:00] [Server thread/INFO]: [Essentials] Status determining class: !net.minecraft.server.v1_17_R1.MinecraftServer
[20:15:01] [Server thread/INFO]: Attempting to convert old kits in config.yml to new kits.yml
[20:15:01] [Server thread/INFO]: No kits found to migrate.
[20:15:01] [Server thread/WARN]: java.lang.NullPointerException: Cannot invoke "java.lang.Class.getMethod(String, java.lang.Class[])" because "nmsClass" is null
[20:15:01] [Server thread/WARN]: at net.ess3.nms.refl.providers.ReflServerStateProvider.(ReflServerStateProvider.java:20)
[20:15:01] [Server thread/WARN]: at com.earth2me.essentials.Essentials.onEnable(Essentials.java:322)
[20:15:01] [Server thread/WARN]: at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:263)
[20:15:01] [Server thread/WARN]: at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:342)
[20:15:01] [Server thread/WARN]: at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:480)
[20:15:01] [Server thread/WARN]: at org.bukkit.craftbukkit.v1_17_R1.CraftServer.enablePlugin(CraftServer.java:495)
[20:15:01] [Server thread/WARN]: at org.bukkit.craftbukkit.v1_17_R1.CraftServer.enablePlugins(CraftServer.java:409)
[20:15:01] [Server thread/WARN]: at net.minecraft.server.MinecraftServer.loadWorld(MinecraftServer.java:608)
[20:15:01] [Server thread/WARN]: at net.minecraft.server.dedicated.DedicatedServer.init(DedicatedServer.java:264)
[20:15:01] [Server thread/WARN]: at net.minecraft.server.MinecraftServer.x(MinecraftServer.java:987)
[20:15:01] [Server thread/WARN]: at net.minecraft.server.MinecraftServer.lambda$0(MinecraftServer.java:307)
[20:15:01] [Server thread/WARN]: at java.base/java.lang.Thread.run(Thread.java:831)
[20:15:01] [Server thread/INFO]: Loaded 25599 items from items.json.

i just want to know fi there is something i can do to resolve that issue lines warns on startup

[JRoy]

See our 1.17 update progress on #4211

In the meantime, 1.17 isn't supported and doesn't work