ARC Connection Issue - Error 1016 / 530 - Port Forwarding Success but ARC fails (ref#XXEIHU)

[Anders_Sorensen (Anders Sørensen)]

Hi! What’s not quite right with Roon?

· Can’t reach my Server, remotes or ARC

Can’t connect to my Server, remotes or ARC

· Other ARC issues

Tell us what's going on

· Hi i can`t connect to ARC here`s a summary what i have tried and done.
Subject: ARC Connection Issue - Error 1016 / 530 - Port Forwarding Success but ARC fails
Core Machine Details:
• OS: Windows 11 (Custom build)
• Connection: Tested with both Wi-Fi and Ethernet (LAN)
Network Setup:
• ISP: Altibox (Home Gateway)
• Router: TP-Link Deco M5 (Running in Access Point Mode)
Troubleshooting performed:
1. Resolved "Multiple NAT" by setting Deco M5 to Access Point mode.
2. Manually port forwarded port 55000 (TCP) in the Altibox portal.
3. Verified the port via CanYouSeeMe.org, which returns "Success" on port 55000.
4. Set Windows Network Profile to Private.
5. Disabled IPv6 on the network adapter.
6. Temporarily disabled Windows Defender and Firewall for testing.
7. Restarted Core, Router, and Modem multiple times.
The issue:
Despite the port being confirmed open by external checkers, Roon ARC still fails with the following diagnostic report:
{
"ipv4_connectivity": {"status":"NetworkError","status_code":530,"error":"error code: 1016"},
"external_ip": {"actual_external_ip":"158.aaa.bbb.ccc","actual_external_ipv6":"null","router_external_ip":"null"},
"natpmp_autoconfig": {"status":"NotFound"},
"upnp_autoconfig": {"status":"NotFound"},
"multinat_autoconfig": {"status":"Failed","error":"No uPnP Routers found on LAN"}
}
Since the port is verified as open from the outside, it seems to be a local handshake issue between Roon and the OS. Any help would be appreciated

"I have confirmed that JRiver Media Center works perfectly with port forwarding on this exact same PC and IP address. External port checks (CanYouSeeMe.org) show 'Success' on my Roon port, but Roon still reports error 1016. This confirms the issue is within the Roon software/OS handshake, not the network."

Tell us about your home network

· As stated before Tp-Link M5 no vpn

[vadim]

Hello @Anders_Sorensen

Welcome to the community.

Thank you for providing such an incredibly detailed and well-structured summary of your troubleshooting. You have done everything exactly right—from setting your Deco to Access Point mode to manually forwarding the port and verifying it externally.

Because CanYouSeeMe.org returns a “Success” on port 55000, we know definitively that the port is open and the Roon Server on your Windows machine is successfully listening. The OS handshake is working perfectly.

Here is what is actually causing the error:

The Cloudflare Diagnostic Issue The 530 and 1016 error codes you are seeing are generated by Cloudflare, our cloud infrastructure provider. Roon relies on this infrastructure to run the automated connectivity test and display the “Ready” status in your settings.

Following a recent widespread Cloudflare outage, this specific testing mechanism is failing for many users. Our engineering team is actively investigating this broader issue to get the diagnostic reporting back online.

Your Next Steps The good news is that the diagnostic test is entirely separate from the actual audio streaming connection. Because you have independently verified that your port is open, the direct tunnel from your phone to your Core should function normally.

Please try the following practical test:

1. Ignore the “Not Ready” diagnostic error in your Roon Settings.
2. Disable Wi-Fi on your mobile phone so it is strictly using cellular data.
3. Open the Roon ARC app and try to load your library and play a track.

Could you please give this a try and let me know if ARC successfully connects and streams your music despite the error message?

[Anders_Sorensen (Anders Sørensen)]

YES..!! Connect right away …

So the problem lays at the auto connect to ARC.

Please forward this if you haven’t.
All the best problem sovle!