You need to agree to the EULA in order to run the server. Go to eula.txt for more info.' This is because the latest Minecraft server now requires users to agree to an EULA.
The EULA specifically forbids you from charging players in exchange for game behaviour that gives them an advantage over others who won't pay or pay different amounts. Cosmetic items are okay, but giving them extra resources, for example, isn't okay. Mojang has a blog post about it here 'Let's talk about monetisation' with a follow-up 'Q&A' there.
To accept the EULA, do the following:
- Login into the Control Panel
- Click Manage on the server you wish to accept the EULA on.
- On the left-hand side, Click File Manager.
- Find the eula.txt file and then click the Edit File icon on the right-hand side.
- Read the contents of the file. Most importantly, read https://account.mojang.com/documents/minecraft_eula
- If you agree to the EULA, change
- Click Save to the save the eula.txt then you should be able to start the Minecraft server.