How to solve Velocity server cannot connect to lobby error?

If there is a connection to the proxy but the lobby does not open, the problem starts after the path between the client and the proxy. Compare Velocity and backserver logs at the same timestamp.

Step by step

1. Check that the lobby address and port are correct in the velocity.toml file. On separate machines, the address 127.0.0.1 does not point to the other machine.

2. Try connecting to the lobby port from the proxy machine. The lobby must be opened and the network rules must allow the proxy source.

3. If TCP route is working, compare proxy settings in modern forwarding mode, secret and Paper. If the error text is a version mismatch, handle it separately.

4. Try entering the proxy and switching to the target. Verify that you have resolved the issue without opening a direct external link to the Lobby.

Keep in mind

Just because the public proxy status appears to be on does not mean that all the servers behind are ready.

Source and tools

• PaperMC: velocity.toml