Most problems with a Terraria server come down to a few causes. Start with the one that matches what you see.
Players cannot join and the game complains about the version, or the connection just fails after a Terraria update
Why: The server is on an older Terraria build than the players. This happens when the server is pinned to a number in Terraria version, or Auto-update server is off.
Fix: Set Terraria version to latest, turn Auto-update server on, and restart. The server updates itself on start and keeps your world.
The server started with a brand new empty world and my old world is gone
Why: World Name was changed. The server creates a new world for any name that has no file. The old world is still on disk.
Fix: Set World Name back to the old name and restart. Your old world loads again.
I changed World Size, Difficulty or World Seed and my existing world did not change
Why: These settings only apply when a new world is generated and never change a world that already exists.
Fix: Create a new world by using a new World Name, with the settings you want chosen first.
The first start takes several minutes and I cannot join yet
Why: The server is generating a new world. Large worlds take the longest.
Fix: Wait until the console finishes generating and the server reports it is listening, then join. Later starts are quick.
I changed the password or MOTD with a console command and it went back after a restart
Why: Console changes last only until the next restart, the server rewrites them from the panel settings on start.
Fix: Set Password and MOTD in the panel settings and restart.
The panel will not accept my password, MOTD, seed or world name
Why: Only plain letters, numbers, spaces and basic punctuation are supported. Accented letters, emoji, double quotes and backslashes are rejected. World Name allows English letters, numbers, spaces and . - _ ' with a 20 character limit.
Fix: Remove the unsupported characters and shorten the value if needed.
I cannot raise Max Players above a number, or the field is greyed out
Why: The player limit comes from your plan and the field is read-only.
Fix: Use Players on the server overview to choose a lower number, or upgrade your plan to raise the limit.
Still stuck?
Open a ticket in the category that fits and include the last 50 to 100 lines of the console. See How to open a support ticket and How to fix a server that will not start.
