So, I switched my server's version from Bukkit 1.12.2 to Bukkit 1.14.2 and after that when I join the world I get kicked from the server after 1-2minutes for Timed Out or java.net.ConnectionException. I wanted to switch the versions again but it said that my world will be deleted so I downloaded my world and tried to upload it but the file is too big (1gb). There are around 1.1k chunks loaded so I tried to delete most of them since mlre than 800 are useless by using MCEdit but the world takes ages to load... Another thing I've tried was installing the plugin ClearLagg and doing /lagg unloadchunks or unusedchunks (I don't remember) but it did nothing.
Does anyone know if there's another way?