Error messages

NodeMP has no numbered errors. What stops you is a sentence from one of three places: a launcher notification, a refusal or kick from the server, or the last line of the helper’s log. This page lists them all; … stands for a part that changes. For the common cases explained step by step, start with When something breaks.

Launcher notifications

A notification has a title naming the step that failed and, under it, the exact reason. Below they are written as title · reason.

Client mod

Message	What happened	What to do
Could not join · client mod is not installed and the directory is unreachable	First join without NodeMP.zip, and NodeMP didn’t answer.	Get online and join again.
Could not join · client mod is not installed and no release has been published yet	First join, and no client mod has been released yet.	Wait for a release.
Could not join · could not start the download: …, the download server returned …, the download stopped: …, the download was N bytes, the release says M, the download is larger than the release says	The download didn’t start or broke off.	Check your connection, VPN or proxy and join again.
Could not join · the downloaded client mod does not match the published checksum	The file arrived damaged.	Join again.
Could not join · LOCALAPPDATA is not set, so BeamNG's user folder cannot be found	A standard Windows setting is missing.	Sign out of Windows and back in.
Client mod could not be updated · Joining with the installed copy.	The check failed, but you have an older NodeMP.zip. A warning only.	If the server refuses the old mod: close the game, then Settings → Launcher → Client mod → Check now.
Could not check the client mod · could not replace …\NodeMP.zip (is BeamNG.drive running?): …	The running game holds the file.	Close BeamNG.drive and click Check now.

Starting a session

Message	What happened	What to do
Could not start the session · could not start …: …	Windows or an antivirus stopped the helper from starting.	Allow NodeMP in the antivirus, or reinstall from nodemp.com/download.
The launcher’s traffic helper stopped · the last line of its log	The helper quit during the join.	Look the line up in Helper exit codes.
You are already on a server: leave the game to join another	A join started while a session was running.	Close BeamNG.drive first.
Connection cancelled	You clicked Cancel.	Nothing.

Connecting

Message	What happened	What to do
Could not connect · Could not reach the server	Nothing answers at that address: the server is off, its port is closed, or a firewall is in the way.	Refresh the list. If it’s your server, check that the port is open for TCP and UDP.
Could not connect · DNS Lookup Failed	The name typed in Direct Connect doesn’t resolve.	Check the spelling, or use the IP address.
Could not connect · server certificate fingerprint mismatch	A server joined by address shows another certificate than last time.	Ask the host. If they reinstalled the server, delete its line from known_servers.json in the launcher’s cache folder.
Could not connect · TLS handshake failed: …, server presented no certificate	Something else than a NodeMP server answered, or the connection broke during the handshake.	Check the address and port and try again. With a VPN, see A bad connection.

Downloading the server’s mods

These come as The server refused the join or Session ended with one of the helper’s own reasons:

Reason	What happened	What to do
Server cannot find …, Server refused … (protected), Server failed to read …	The server lists a mod it can’t or won’t send.	Tell the host.
Mod '…' is protected: the server does not send it, so it has to be put in the cache folder by hand: …	The host wants players to get this mod themselves.	Get the zip from the host and put it into the folder the message names.
Failed to verify "…"	A downloaded mod didn’t match what the server announced, twice.	Tell the host. Removing the file under Content forces a fresh download.
Received corrupted download confirmation, aborting download., Download announcement does not match the mod list, aborting download.	The server’s answer during the download didn’t add up.	Join again; tell the host if it repeats.

The server list, the cache and updates

Message	What happened	What to do
Could not reach NodeMP	The server list didn’t load; the line under it names the address used.	Check your connection and VPN. Direct Connect still works.
Could not remove the file · could not remove …: …, … is no longer in the cache, … is not a cached content file	Removing a file under Content failed; the first one usually means the game has it open.	Close the game and try again.
Could not install the launcher update · the downloaded installer does not match the published checksum, the download stopped (…); it resumes on the next try, the download stopped at N of M bytes; it resumes on the next try	The update didn’t download completely.	Try again; it continues where it stopped.
Could not find a BeamNG.drive install. Browse to it, or launch the game once so Steam writes its path.	Under Settings → Game: no game found.	Browse to the game folder, or start the game once through Steam and click Find it.
No Bin64\BeamNG.drive.x64.exe in this folder	Under Settings → Game: that isn’t the game’s main folder.	Pick the folder that holds Bin64\.

The server’s refusals and kicks

The server says no in plain words. At the door the launcher shows it as The server refused the join; during a session the game says the session ended and the launcher comes back with Session ended. The server’s log has the same text as <name> kicked — <reason>.

For version and game-file problems the launcher turns the server’s sentence into advice with a button; those rows say what is shown, and the server’s own words stay under Details. Plugins can kick with their own text, which you then see as it is.

Reason	When	What to do
Protocol version mismatch: launcher speaks v22, server speaks v21 - update the outdated side	The launcher and the server speak different protocol versions (the numbers are the real ones). With the launcher behind, shown as This server needs a newer launcher — update now with Update now; with the server behind, as This server runs an older NodeMP server (protocol v21; this launcher speaks v22).	Update now updates the launcher and joins again. If the server is behind, tell its host.
Your NodeMP mod is out of date for this server (it speaks wire protocol …, the server …). Reinstall it from the launcher.	Your client mod speaks another protocol version than the server.	Close the game, Settings → Launcher → Client mod → Check now, join again.
Server full!	The server has as many players as it allows.	Use the Free slots filter, or wait.
The server is starting up; join again in a moment.	The server is still loading its plugins.	Try again in a minute.
Server shutdown	The server is stopping; everyone on it gets this.	Wait for the host to bring it back.
You are banned from this server	Your address or account is on this server’s ban list, without a reason. A ban with a reason shows that reason instead.	Ask the host.
This server requires a NodeMP account: sign in to the launcher and join again	The server doesn’t allow Test Drive, and you joined without an account.	Settings → Account → Sign in, or use the No account needed filter.
Your join ticket was not accepted (join ticket invalid or expired). Join again from the launcher to get a new one	NodeMP didn’t accept the one-time join ticket; the brackets say why.	Join again.
The server could not verify your account with the directory (…). Try again in a moment	The server couldn’t reach NodeMP to check your account.	Try again in a moment.
Resume rejected	Your connection broke, and the server wouldn’t take the reconnect back: the old session was already gone.	Join again.
Resume rejected: too many failed attempts, try again later	Too many failed reconnects from your address in a short time.	Wait a minute, then join again.
Connection refused	A plugin turned you away without a reason; with a reason, you see that reason.	Ask the host.
Your BeamNG install does not match the game's own file list (3 files differ). Verify the game's files in Steam and try again. …	Some game files differ from the game’s own list. The number is real.	Verify the game files in Steam.
Your BeamNG install changed while you were playing, and this server requires it to match the game's own file list (1 file differs). …	The same check, repeated during the session, found a change.	Undo what you installed; verify the game files.
Game files do not match this server's reference (3 problems). userfolder:vehicles/pickup/pickup.jbeam (overlay), …	A strict server: your install or user folder differs from the host’s clean copy. Up to three examples follow. Shown as Your game files do not match this server's reference (3 problems) · vehicles/pickup/pickup.jbeam, with the first problem in words and a command that lists them all.	See A strict server refuses you.
Game files changed while you were playing and no longer match this server's reference (1 problem). …	The strict check, repeated during the session, found a change. Shown as Your game files changed while you were playing and no longer match this server's reference (1 problem).	Undo the change and join again.
Your launcher checked your BeamNG install against a different reference manifest than this server uses (checked against reference manifest … but this server uses …). Reconnect so it fetches the current one.	The host replaced the server’s reference manifest since your last visit. Shown as This server's reference manifest changed — join again.	Join again.
This server requires the strict check of your BeamNG install, but your launcher ran only 'size'. Update your launcher and try again.	A strict server got the result of a lighter check. Shown as This server needs a newer launcher — update now.	Update now, or reinstall from nodemp.com/download.
This server requires a strict check of your BeamNG install but has no integrity manifest to check it against. Ask the host to run `Node-Server --gen-integrity <gamedir>` and put the file in the server's integrity folder.	The host turned on the strict check without the file it needs.	Tell the host (Strict file check).
This server has integrity manifests for 2 game versions (0.39.4.0, 0.39.3.0) and cannot tell which one you run. Ask the host to keep exactly one manifest in the server's integrity folder.	The host keeps files for more than one game version.	Tell the host.
Unknown integrity manifest requested	The launcher asked for a file the server doesn’t have, usually one the host just replaced. Shown as The server would not send its reference manifest.	Join again in a moment; tell the host if it repeats.
Too many integrity manifest requests	The launcher asked for that file too often in one session. Shown as The server stopped sending its reference manifest (asked too often).	Join again in a moment; reinstall the launcher if it repeats.
This server requires a check of your BeamNG install, which could not be completed: …	The check couldn’t run; the text after the colon says why. Shown as BeamNG's user folder was not found, Could not download the server's reference manifest, The server's reference manifest is out of date or Your game files could not be checked.	Follow the advice under it, then join again.
Kicked, Kicked by the server, Kicked by module	A plugin, the server console or a native module removed you without a reason.	Ask the host.
Banned	A plugin banned you without a reason.	Ask the host.
Packet rate limit exceeded	Your game sent packets faster than the server allows.	Join again; report it if it repeats.
Disconnected after failing to receive packets	The server couldn’t deliver data to you.	Join again.
TCP send of MODS_INFO failed	The server couldn’t send its mod list; the connection was already gone.	Join again.
Expected HELLO, Malformed HELLO, Expected IDENTITY after HELLO, Unknown packet type during handshake, Frame length cap exceeded, Per-type body cap exceeded, Malformed frame, Packet decode failed, Sent a compressed packet that does not decompress, Malformed game verification report	The launcher sent something the server doesn’t accept. Only a modified or broken launcher does that.	Reinstall the launcher from nodemp.com/download.

Session ended with no reason at all means BeamNG.drive was closed.

Helper exit codes

The helper is the launcher’s background part that does the joining. When it quits during a join, the launcher shows The launcher’s traffic helper stopped with the last line of its log. The number itself is only visible when you start the helper by hand. The full log is %LOCALAPPDATA%\NodeMP\helper\logs\launcher.log.

Code	Last log line	Meaning	What to do
0	game closed - launcher closing soon	BeamNG.drive was closed and the session ended.	Nothing.
1	Launcher.cfg is there but cannot be read; check its permissions, or delete it to start from the defaults, Launcher.cfg is not valid JSON; fix it, or delete it to start from the defaults	The helper’s settings file is unreadable or broken.	Delete Launcher.cfg; the helper writes a fresh one.
1	Cannot create the mod cache …: …. Point CacheDirectory in Launcher.cfg at a folder you can write to.	The folder for downloaded mods can’t be created.	Fix the folder’s permissions, or set CacheDirectory in Launcher.cfg.
2	BeamNG.drive was not found. Choose its folder (the launcher's Settings > Game, or --game-dir), or start the game once so it records where it is.	No game install found. The helper quits after 10 seconds.	Set the folder under Settings → Game, or start the game once through Steam.
2	The game could not be started (through Steam, or by its executable); the launcher closes in 5 s.	Neither Steam nor the game’s own executable started BeamNG.drive.	Verify the game files in Steam and check Settings → Game.
5	Another Node-Launcher is already running on port 4444 - closing	A second helper was started while one is running.	Close the other one (or BeamNG.drive with it) and try again.
6	port 4444 is in use by another program …	Another program holds the local port the game talks to the helper on.	Close that program; the message names a command that shows which one it is.

The helper’s game-file check can also run on its own (the Copy button under a strict refusal gives the command). It exits with 0 when the install is clean (game files verified: …), 1 when something differs (game files DIFFER: …) and 2 when the check couldn’t run (cannot read the manifest file …, not a reference manifest: …, could not check: …).