# Diagnostic errors


> What each network diagnostic error on a Screenly Player means, and the causes worth checking first for each one.
A player runs its own network checks and reports which one failed. Each error points at a different layer, so the message narrows the search considerably.

## Wired connection

The player cannot establish a link or get an IP address over ethernet.

Check the cable at both ends, including whether it is fully seated rather than partly inserted. Then check the switch port: the player may need allowlisting on your network, or the port may be on the wrong VLAN.

## Wireless connection

The player cannot connect over Wi-Fi.

The usual causes are a wrong password, a wrong or unfindable SSID, a band the board does not support, an access point that is out of reach, or a player that needs allowlisting.

Most of these come from typing network details by hand into a configuration file. Use a USB keyboard instead where you can, because it lets you pick the network from a list rather than spelling out the SSID.

## Time server (NTP) connection

The player cannot reach a time server, so it cannot set its clock.

Check that port 123 is open and that `ntp.ubuntu.com` is allowed. Then check for an error in a manual NTP configuration, or a routing problem reaching the server.

Accurate time is not cosmetic here: security and scheduled playback both depend on it. See [Configure time servers](/docs/screenlyos/networking/guides/configure-time-servers/).

## Screenly backend connection

The player cannot reach `api.screenlyapp.com`, `mtls.screenlyapp.com`, or `ws.screenlyapp.com`.

Check whether those hostnames are blocked by your firewall, whether there is a DNS mistake in a manual network configuration, or whether the player is on the wrong VLAN.

## Operating system connection

The player cannot reach the resources Canonical provides for Ubuntu Core.

Check the [hostnames and ports](/docs/screenlyos/networking/reference/hostnames-and-ports/) are allowlisted in full, including the Ubuntu entries, and that the player is on the right VLAN.

## If an error persists

Once you have confirmed the requirements are in place, power cycle the player: disconnect it for 20 to 30 seconds and reconnect. If it comes back with the same error, {{< support-link "contact support" >}}.