Skip to content
MC-Vector

Common Errors

Server Won’t Start

”Java not found” or “Invalid Java path”

Cause: No Java is assigned to this server, or the configured path no longer exists.

Fix:

  1. Open General Settings for the server.
  2. Under Java Version, click “Manage Java”.
  3. Download the appropriate version (Java 21 for Minecraft 1.21+).
  4. Select it in the dropdown and save.

”Failed to start server process”

Cause: The server JAR is missing, corrupt, or the configured path is wrong.

Fix:

  1. Navigate to the Files tab and confirm server.jar (or the configured JAR) exists.
  2. If missing, use the Version Upgrade Wizard or re-create the server to re-download the JAR.

Server starts but immediately stops

Cause: The EULA has not been accepted, or server.properties has an invalid value.

Fix:

  1. Open the Files tab and open eula.txt.
  2. Change eula=false to eula=true and save.
  3. Check the Console for the specific error line before the shutdown.

Server Crashes

Repeated crashes with “Out of memory” in logs

Fix: Increase the memory allocation in General Settings → Memory. Ensure your system has sufficient free RAM.

Crash after installing a plugin

Fix:

  1. Open the Files tab → plugins/ folder.
  2. Remove the newly added plugin JAR.
  3. Restart the server and check if it stays online.
  4. Check the Console for the error before the crash — it usually names the offending plugin.

Auto-restart keeps looping

Cause: A plugin or config issue causes an immediate crash on every start.

Fix: Disable Auto-Restart in General Settings temporarily, fix the root cause, then re-enable it.

Connection Issues

Players cannot connect to the server

  1. Confirm the server is Running (green status in Dashboard).
  2. Check the server port in Properties → Server Port (default: 25565).
  3. If using Ngrok, verify the public address is current — it changes on every Ngrok restart.
  4. If using a router, confirm port forwarding is configured for the correct port.

”Connection refused” when using Ngrok

Fix:

  • Verify the Ngrok authtoken in General Settings.
  • Free Ngrok accounts allow only one active tunnel — check you don’t have another session open.
  • Re-enable the Ngrok toggle in General Settings to force a reconnect.

MC-Vector App Issues

MC-Vector won’t launch (macOS Gatekeeper)

Fix: Open System Settings → Privacy & Security and click “Open Anyway” next to MC-Vector.

”Port already in use”

Cause: Another process (or another MC-Vector server) is using the same port.

Fix: Change the port in General Settings or stop the conflicting server.

Backup fails with “permission denied”

Cause: MC-Vector doesn’t have write permission to the backup destination.

Fix: Check that the server’s data directory is writable by your user account.

Logs and Diagnostics

The Console tab is the first place to check for any server error. Look for lines containing ERROR, FATAL, or Exception near the time of the problem.

For MC-Vector app-level issues, quit and relaunch the app. If problems persist, open a GitHub issue with a description and the relevant log lines.