Very often we have to face a similar problem, because we all want to add a little variety to the classic game. Everyone wants to dilute the look and so on. Therefore, they resort to a variety of types of changes. Try to remove the auxiliary mods. Auxiliary mods are those that see only you and they don`t add anything to the game itself. Also try reloading it, other options are unknown to me =( Try to explore a specialized platform that provides Minecraft Server List for free for a more comfortable game.