This article will describe how to agree to the minecraft EULA

Step 1 Log into your game panel here
Step 2 Select your server then press start
Step 3 Press "Accept" when you this box popup

Acceptance of EULA ( Alternative if Box shown above does not popup )

Step 1 Navigate to the File Manager
Step 2 Locate and select eula.txt
Step 3 Change the file from eula=false to eula=true

Note: This is not guaranteed to fix all issues but is the most common initial start-up issue