TP-Link Deco X55 the Deco app shows an error while setting up the main Deco
Cause 1 of 2The app reports that the Ethernet cable is not connected (Unable to complete WAN setup). Source: Unable to complete WAN setup; Error Code: Ethernet Cable is Not Connected, p. 1
First checkUse a different Ethernet cable between the modem and the main Deco.
Causes and checks
The app reports that the Ethernet cable is not connected (Unable to complete WAN setup). Source: Unable to complete WAN setup; Error Code: Ethernet Cable is Not Connected, p. 1
- Use a different Ethernet cable between the modem and the main Deco.
- Use a different Ethernet port on the main Deco.
- Connect a laptop to the modem directly to verify that the modem provides service.
The app reports that it failed to create the Wi-Fi network (Failed to connect to TP-Link Cloud, Unable to apply your network settings, or Failed to create Wi-Fi network). Source: Unable to create WiFi network, p. 1
- Check the LED on the main Deco. If it is solid green or white, the Wi-Fi network exists: close the Deco app and join the new network from the phone's Settings > Wi-Fi page.
- If the LED is still pulsing blue, run the setup again with a different Wi-Fi name.
All 2 causes checked. Contact TP-Link Technical Support.
Service
If the checks above do not clear it, contact TP-Link Technical Support, tp-link.com/support. Contact Technical Support page at tp-link.com/support, and the Help center of the Deco app. Source: About This Guide, More Info, p. 1
Other Deco X55 problems
- The main Deco does not pulse blue during setup2 causes in the manual. First: the LED on the main Deco is not pulsing blue.
- A satellite Deco does not join the networkThe app shows Failed to Add This Device or Couldn't Find Any New Deco while you add a satellite.
Sources
- User Guide, AX3000 Whole Home Mesh Wi-Fi 6 System Deco X55 (EU, V3.0). TP-Link Systems Inc. Document 1910013645, revision REV3.0.0, 2024, 16 pages, en-US. static.tp-link.com (PDF). Retrieved 13 November 2026.
- What Do Deco LED Colors Mean?. TP-Link Systems Inc. Document FAQ 1464, revision Last updated 2017-01-17, 2017-01-17, 1 pages, en-US. tp-link.com. Retrieved 13 November 2026.
- TP-Link Deco Solid Red Light: What It Means and How to Fix It. TP-Link Systems Inc. Document FAQ 3672, revision Last updated 2023-06-15, 2023-06-15, 1 pages, en-US. tp-link.com. Retrieved 13 November 2026.
- Main Deco Failed to Complete Setup. TP-Link Systems Inc. Document FAQ 2239, revision Last updated 2023-07-12, 2023-07-12, 1 pages, en-US. tp-link.com. Retrieved 13 November 2026.
- How to Reset Deco: Reset or Reboot Your Deco Whole-Home Wi-Fi System. TP-Link Systems Inc. Document FAQ 1457, revision Last updated 2026-10-08, 2026-10-08, 1 pages, en-US. tp-link.com. Retrieved 13 November 2026.
- Deco Wi-Fi Settings. TP-Link Systems Inc. Document FAQ 1591, revision Last updated 2026-04-17, 2026-04-17, 1 pages, en-US. tp-link.com. Retrieved 13 November 2026.
- How to Update or Upgrade TP-Link Deco Firmware (3 Methods). TP-Link Systems Inc. Document FAQ 1599, revision Last updated 2026-08-24, 2026-08-24, 1 pages, en-US. tp-link.com. Retrieved 13 November 2026.
- Error When Adding a Deco Satellite Node: How to Fix It. TP-Link Systems Inc. Document FAQ 1447, revision Last updated 2026-05-07, 2026-05-07, 1 pages, en-US. tp-link.com. Retrieved 13 November 2026.
Page numbers are the numbers printed in the manual. Where this page and the manual differ, follow the manual.