Open the Console tab first. When BeamMP prints a line the panel knows, a card above the Console explains it in plain words and links to the fix. The causes below are the ones that card and the BeamMP server list card on Overview report.
The server stops right after Start
A box says the server will not start without an auth key
Why: no BeamMP Auth Key is saved. BeamMP refuses to start without one, even for a private server.
Fix: get a free key and paste it on Overview: Your BeamMP server will not start without an auth key.
The server could not read its settings
Why: ServerConfig.toml has a line BeamMP cannot read, almost always from a hand edit. The Console shows Error parsing config file value with the line number under it, then Closing in 10 seconds.
Fix: open ServerConfig.toml in Files, remove the line the Console points at, save and start again. Make your changes in Settings instead: the panel writes the name, map and other options into that file at every start.
The server could not open its game port
Why: another program holds the port, most often a copy of this server that had not finished shutting down. The Console shows bind: Address already in use.
Fix: wait a minute and start again. If it keeps happening, check on Ports & Network that the game port is the one assigned to your server, and contact support with the line.
A mod file is broken
Why: a folder whose name ends in .zip in the mods folder stops BeamMP at start. Mods & maps shows A folder named ... stops the server.
Fix: click Remove the folder on Mods & maps, or rename it in Files, then start the server.
The BeamMP server program crashed
Why: BeamMP-Server stopped with a crash, its terminate called line.
Fix: start again. If it repeats, a mod or plugin you added last is the likely cause: switch it off on Mods & maps and start again.
The mod list file is damaged
Why: Resources/Client/mods.json cannot be read. It only holds your mods' hashes.
Fix: delete mods.json in Files. The server builds it again at the next start.
The server runs but players cannot join
Nobody can find it in the list
Why: the server is private, the key was refused, or the server only just started. BeamMP lists a new server within 1 to 3 minutes.
Fix: use Direct connect with the address meanwhile, and see Your BeamMP server does not show in the server list.
Players cannot join after an update
Why: the player's launcher or game, or your server, is out of date. The Play with friends card says Everyone needs the same game version or branch as the server.
Fix: players update their BeamMP launcher and BeamNG.drive. Restart your server so it gets the newest BeamMP build: How to update your BeamMP server.
Players are dropped while downloading mods
Why: the mod pack is big, a zip is broken, or a mod is packed wrongly.
Fix: see Players are stuck downloading mods on your BeamMP server.
A player is turned away at the door
Why: they are banned, not on the whitelist, or a guest while guests are off. The Chat tab of the Players page shows them under Turned away with the reason.
Fix: lift the ban, add them to the whitelist, or ask them to sign in to BeamMP: How to unban a player on your BeamMP server, How to turn on the whitelist on your BeamMP server, How to stop guests joining your BeamMP server.
The server is full
Why: every slot is taken. Online now on the Players page shows, for example, 6 of 6.
Fix: raise the slots with Edit slots on Overview, up to your plan's limit.
Still stuck?
Open a ticket with the last 50 to 100 lines of the Console and the text of the card above it. See How to open a support ticket. Every other problem is in BeamMP server problems and fixes.
