I got this error in my 1.8.9 minecraft server while using server.pro and i don't know how to fix it any ides?

I got this error in my 1.8.9 minecraft server while using server.pro and i don't know how to fix it any ides?

Read more: https://minecraftzone.net/qa/server/i-got-this-error-in-my-1-8-9-minecraft-server-while.html