Articles on: Troubleshooting

Why is my Klipper-powered printer offline?

Why is my Klipper-powered printer offline?


This guide helps troubleshoot why your Klipper-based printer shows offline in SimplyPrint.


How SimplyPrint connects


SimplyPrint connects through Moonraker - not Klipper directly.


SimplyPrint ←→ Moonraker ←→ Klipper ←→ Printer


Mainsail and Fluidd also talk to Moonraker. If they can control your printer, Moonraker is working.



Start here: Where is the problem?


Step 1: Can you access Mainsail or Fluidd?


Open your printer's web interface in a browser.


  • Can't access it? → Your printer or Moonraker has issues - not a SimplyPrint problem
  • Can access it and printer works? → Continue to Step 2


Step 2: Is [simplyprint] in moonraker.conf?


In Mainsail or Fluidd, open the config editor and check moonraker.conf for:


[simplyprint]



Step 3: Check moonraker.log for errors


Download moonraker.log from Mainsail/Fluidd and search for "simplyprint".


Mainsail: Machine > Logs > moonraker.log (download icon)


Fluidd: Settings > Logs > moonraker.log




Quick reference


Symptom

Likely cause

Solution

Printer never connected

[simplyprint] missing

Add to moonraker.conf

Was working, now offline

Moonraker restarted or config changed

Restart Moonraker

"Klippy not connected" in Mainsail/Fluidd

Klipper issue (not SimplyPrint)

Fix Klipper first

Offline after power outage

Services didn't start

Restart services

SimplyPrint errors in logs

Various

Check common errors



1. Add [simplyprint] to moonraker.conf


Using Mainsail or Fluidd


  1. Open config editor
  2. Open moonraker.conf
  3. Add this line anywhere:
   [simplyprint]
  1. Save
  2. Restart Moonraker


Note: That's all you need - just [simplyprint] with nothing else. The component is built into Moonraker.


Component doesn't work?


Your Moonraker may be outdated. Update using the update manager in Mainsail/Fluidd.



2. Restart Moonraker


First: Try restarting Moonraker - this fixes many connection issues.


Many issues are fixed by restarting after config changes.


Mainsail: Power icon (top right) > Restart Moonraker


Fluidd: Settings > Services > Restart Moonraker


Make sure you saved config changes before restarting.



3. Common errors in logs


Download moonraker.log and search for "simplyprint":


Error

Meaning

Fix

"Connection failed"

Can't reach SimplyPrint servers

Check internet connection

"Klippy Host not connected"

Klipper isn't running

Fix Klipper first

"Authorization error"

Moonraker blocking connection

Check [authorization] in moonraker.conf

No SimplyPrint entries

Component not loaded

Add [simplyprint] and restart



4. Network issues


Internet connection


Your printer needs internet for SimplyPrint. If Mainsail/Fluidd works but SimplyPrint doesn't, check connectivity.


WiFi stability


Unstable WiFi causes random disconnections:

  • Try Ethernet instead
  • Move closer to router
  • Check for interference


Firewall


SimplyPrint connects outbound - no ports need opening. But make sure outbound connections aren't blocked.



After a power outage


Services may not have started correctly.


  1. Check if you can access the web interface
  2. If yes, restart Moonraker from interface
  3. If not, wait a few minutes for boot to complete



Advanced: SSH troubleshooting


If you have SSH access:


Check if Moonraker is running:

systemctl status moonraker


Restart services:

sudo systemctl restart moonraker


View logs:

tail -100 ~/printer_data/logs/moonraker.log



Getting help


Gather this first


  1. Download moonraker.log from Mainsail/Fluidd
  2. Copy moonraker.conf (remove sensitive info)
  3. Screenshot of offline printer in SimplyPrint
  4. What you've tried


Support




Something unclear or missing in this guide? Let us know on Discord.





Updated on: 09/01/2026

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