Connection Failed Errors

General Network Checklist

Before diving into protocol-specific issues, run through these checks:

• Mac and target device are on the same network subnet (e.g., both on 192.168.1.x)
• Ethernet is being used (Wi-Fi is a common source of intermittent failures)
• macOS firewall is not blocking CueSync — check System Settings → Network → Firewall
• No VPN is active (VPNs often change routing and block LAN broadcast)
• Target device (console, node, software) is running and listening

Art-Net Connection Failed

Symptom: the Art-Net output reads Unreachable or Offline in Network → Outputs, or the target console receives no DMX.

1. Verify the destination IP in CueSync matches the console's IP exactly.
2. Confirm UDP port 6454 is open — test with: nc -zuv [IP] 6454 in Terminal.
3. Remember that a green Art-Net output proves that CueSync sent the packet, and no more, because UDP has no acknowledgement. Fire a Manual-trigger cue with an Art-Net action (a channel and a value of 255) and watch the node or fixture.
4. Check the console's Art-Net input is enabled and universe number matches CueSync.

sACN Connection Failed

Symptom: sACN universe shows no data on receiver.

1. Verify multicast is enabled on your network switch (some managed switches block multicast by default).
2. Try unicast mode with the receiver's IP if multicast is blocked.
3. Confirm the universe number matches exactly on both sides.
4. Check the receiver's priority settings — a higher-priority source may be overriding CueSync.

OSC Not Received

Symptom: Target application (Resolume, QLab, etc.) does not respond to CueSync OSC output.

1. Confirm OSC input is enabled in the target application's preferences.
2. Verify the port number matches — the most common mistake is a port mismatch.
3. Check the target is listening on the correct IP (some apps only listen on specific interfaces).
4. Use a free OSC monitor app (e.g., Protokol) to confirm packets are arriving.

grandMA3 Not Responding

1. Use a grandMA3 (UDP) output — a TCP output may never connect.
2. On the console's OSC line, enable both Enable Input and Receive Command, leave Prefix empty, and check the OSC page's Interface names the network your Mac is on.
3. Fire a harmless cue and watch the desk. See the grandMA3 Setup Guide for the full steps.

Diagnosis Steps

If problems persist:

1. Open Network → Outputs, click the affected output and press Test Connection (or Test All in the quick actions bar) — confirm it reports success, then read its recent connection events on the Monitor tab.
2. Use Wireshark on the Mac to capture network traffic and verify packets are leaving the interface.
3. Ping the target device to confirm basic IP connectivity.

Still Stuck?

Contact support with:

• CueSync version (CueSync → About CueSync, or Settings → About)
• Protocol type and target application/device
• Your network topology (same machine / same switch / different subnet)
• A screenshot of the output's editor in CueSync (Network → Outputs)