Hey Joronot!
You can play on 1.13.2 by going to:
Your Servers Panel. (on Minehut.com)
Choose your server.
Go to Plugins (on the left hand side)
Search for, ProtocolSupport, ProtocolSupportLegacyChest, ProtocolSupportStuff
Install.
-Hopefully your problem is solved after a restart of your server, and you should be able to join.-