Fix "FAILED TO BIND TO PORT" on a Minecraft server

"FAILED TO BIND TO PORT" means the server tried to listen on an address or port it cannot use. On Schokr, the fix is almost always to make server-port match your server's allocated port and leave server-ip empty.

The error

[Server thread/WARN]: **** FAILED TO BIND TO PORT!
[Server thread/WARN]: The exception was: java.net.BindException: Address already in use
[Server thread/WARN]: Perhaps a server is already running on that port?

You may also see Cannot assign requested address instead of Address already in use.

Why it happens on a hosted server

Each Schokr server has a port allocation, shown in its Network section. Your server may only listen on its own allocated address and port. It cannot open a port it was not given, and it cannot use a port another process is using.

Fix 1: match server-port to your allocation

Open your server's Network section and note the port of the primary allocation, for example 25571.
Stop the server.
Open server.properties in the file manager.
Set server-port to that number:

server-port=25571

Start the server.

Fix 2: leave server-ip empty

server-ip should normally be blank:

server-ip=

If it contains an IP address the server does not own (such as one copied from another host or your home network), you get Cannot assign requested address. Clearing it makes the server listen on all of its available addresses.

Fix 3: check plugins and mods that open ports

Some plugins and mods open their own ports: web maps, voice chat mods, query or RCON, web panels and Geyser for Bedrock players. If one of these is set to the same port as the game, or to a port you have not been allocated, it can fail to bind, or take the port before Minecraft does.

Look at which plugin or mod the error appears next to in the log.
Set that plugin to use a different port.
Give it its own extra allocation from the Network section. Extra allocations cost 25 credits each, or are unlimited with Schokr One.

Geyser is a special case: it uses UDP, so it can share the same port number as the Java server. Check Geyser's own documentation for the setup you want.

Fix 4: a previous process is still running

Rarely, the old server process has not fully exited when you start again, for example after a crash during shutdown. Use the kill option in the console power controls, wait a few seconds, and start the server again.

BungeeCord proxies

On a BungeeCord server the port is set in config.yml under listeners, not in server.properties:

listeners:
- host: 0.0.0.0:25571

Make the port match the proxy's allocation.