Hello Aternos, our plugin ServerControl Reloaded newly have requires TheAPI plugin installed on server or ServerControlReloaded plugin will doesn't work.
So versions above 6.0 will not work without this plugin.
Plugin is available on Spigot:
Plugin name: TheAPI
Link: https://www.spigotmc.org/resources/theapi.72679/
Description: Plugin is based as an API for plugins, the plugin itself has no functionality except for the mini part of Mutliverse/ServerControlReloaded more precisely the ability to create, remove, unload and load the world.