It says there are on errors, but it isn't showing the actionbar.
on join:
set {_shortenedtime} to shortentime("%{playtime::%player's uuid%}%")
send actionbar "&4Health: &c%letterednum({health::%player's uuid%})%&c/%letterednum({maxhealth::%player's uuid%})% &7| &3Regen: &b%letterednum({regen::%player's uuid%})% &7| &5Strength: &d%letterednum({strength::%player's uuid%})% &7| &6Kills: &e%{kills::%player's uuid%}% &7| &2Playtime: &a%{_shortenedtime}%" to player
Soon after I'm finished with my RPG server, I'll make a call of duty server with all 3 gamemodes, (Campaign, Multiplayer, Zombies). It will be a big project but I hope to get it done successfully.
Try creating a new world, by going to the panel, then file manager, and delete the world you were last in file. (EX: You were in world so you delete the world file)
There maybe something inside of the game that is preventing you, or anyone from joining. Try resetting your server by going onto the server panel, and click "Reset Server".