Only those with admin rights can see the join Messages

This plugin doesn't require any permission to see Join/Leave-Message. Maybe there is another plugin which blocks the Join messages.

Do only Join-Messages not work or both Join- and Leave-Messages.

Please provide the following information so that I can help you furthermore.

• Minecraft-Server Version
• Minecraft-Server Flavor (Bukkit or Spigot ...)
• Plugin Version
• Plugin config file
• List of installed plugins (use /plugins)

Thank you very much.