chunks not loading

[Itz_Hamza]

whenever the server starts the chunks load and then unload and eventually it kicks you out of the whole thing. I've tried downloading the world file and starting a new one. I've tried hibernating the server and relaunching. I've tried repairing files. I've tried absolutely everything but every time I do it the server crashes.  It usually says "could not connect to a default or fallback server" but sometimes it says connection timed out, etc. Please help as this server has months of progress for multiple players.

[_Tarna_]

Did you ever change the tickspeed of your server? Run the command /gamerule randomTickSpeed 3 in console while the server is online but do not join. And make sure the command is exactly like that since it is case sensitive. After running the command, join the server.