Screens uses standard networking technologies such as NAT-PMP, PCP and UPnP to automatically configure your router and make your Mac reachable from anywhere.
If automatic setup fails, one of the following errors may be displayed.
No Router Configured
No router was found on your network.
This usually means that your Mac is connected directly to the internet, connected to a network that does not use a router, connected to an iPhone personal hotspot, or that the router could not be detected.
Possible Solutions
- Verify that your Mac is connected to your local network.
- Restart your router.
- Temporarily disable VPN software and try again.
- If you're using a personal hotspot, automatic setup may not be available.
Port Mapping Disabled
Your router supports automatic setup, but port mapping is currently disabled.
Possible Solutions
- Enable NAT-PMP, PCP or UPnP in your router's settings.
- Some routers require additional permissions before applications can create port mappings.
- Restart your router after changing the settings.
See your router-specific instructions article for additional information.
Port Mapping Unsupported
Your router does not support automatic port mapping.
This usually occurs on older routers or networks managed by your internet provider.
Possible Solutions
- Use an alternative solution such as Tailscale or NordVPN instead.
- Configure port forwarding manually (requires the standalone version of Screens Connect).
- Contact your internet provider to determine whether automatic port mapping is supported.
Operation Timed Out
The router did not respond before the operation timed out.
This is often caused by temporary network issues, router firmware problems, or a busy router.
Possible Solutions
- Wait a few moments and try again.
- Restart your router.
- Restart your Mac.
- Verify that your Mac is connected directly to the router and not through another device.
Service Not Running
The system service required to perform automatic setup is not currently running.
Possible Solutions
- Restart your Mac.
- Install the latest macOS updates.
- If the problem persists, contact Apple Support.
Double-NAT Detected
Your network appears to be using more than one router.
Automatic setup may succeed on one router but fail on another.
Possible Solutions
- Remove unnecessary routers from your network.
- Place one of the routers in bridge mode.
- Configure port forwarding on both routers.
- Use an alternative solution such as Tailscale or NordVPN instead.
Blocked by Firewall
A firewall prevented communication with your router.
Possible Solutions
- Temporarily disable third-party firewall software.
- Verify that security software is not blocking Screens.
- Restart your Mac and try again.
Invalid / Port Mapping Failed
The router rejected the port mapping request.
This may occur when using a personal hotspot, on networks that do not support automatic setup, or when the router is configured to reject port mapping requests.
Possible Solutions
- Verify that NAT-PMP, PCP or UPnP is enabled on the router.
- Restart the router and try again.
- Try another network.
- Use Tailscale if automatic setup is unavailable.
NAT Traversal Unavailable
The network does not support automatic remote access setup.
This can occur on some managed networks, mobile networks, or networks where automatic port mapping is unavailable.
Possible Solutions
- Verify that port mapping is enabled on your router.
- Try another network.
- Use an alternative solution such as Tailscale or NordVPN instead.
Incompatible Daemon
The system service responsible for automatic setup is incompatible with the current version of macOS.
Possible Solutions
- Install the latest version of macOS.
- Restart your Mac.
- Install the latest version of Screens.
Bad Parameter
The request sent to the router was invalid.
This error is uncommon and is usually caused by an issue with the router or the network configuration.
Possible Solutions
- Restart your router.
- Restart your Mac.
- Verify that the router firmware is up to date.
Unknown Error
An unexpected error occurred while attempting to configure your router automatically.