Troubleshooting Zebra Printers

Below is a list of common issues and their resolutions.

Supported Printers:

  • Zebra QLn420 (WiFi)
  • Zebra QL420+ (WiFi)


Scenario 1: Page Cannot Be Found/404 Error when pressing print.

When you press print on the invoice, the address bar at the top of the mobile device should resemble something similar to http://localhost:8080/print4inch.php... 

If after pressing print you get a "page cannot be found" or "404 Error", the likely culprit is the Droid app hasn't been started yet. 

Go back to the home screen of the device and open the application list. (Usually a small circle icon with 4 or 6 squares inside it). 

Look for the DroidPHP app and tap on it and then press "Start Server".

 Scenario 2: After pressing print, you see a white page with a blue border at the top labeled RouteStar or Print with 1 or more error messages on it.

This issue is mainly caused with the tablet cannot communicate with the printer. The areas to check are:

  • Make sure Tablet and Printer are connected to the same MiFi device.
  • Check on the Printers LCD screen and make sure it has an IP address.
  • Check the Preferences option of the mobile device and make sure the Printer IP field matches the printers.*See Note Below*
  • Incorrect installation of


*NOTE* - Anytime you change a setting on the Preferences page, the change will not take affect until you completely LOG OUT of RouteStar and log back in.  


Scenario 3: If you press print and only see a "print preview" and no invoice prints.

 This is a quick fix. Log into the RouteStar App on the mobile device and tap on the "Preferences" button.


On the next screen, make sure the Printer Type is set to Zebra 4inch and make sure you type in the Printer IP and press save.

Once you have pressed save, tap on the back button in the top left corner followed by tapping the log out button.

Now log back in and try to re-print the invoice.


Error 512:

If you get an error 512 while printing you need to make sure the task and or invoice has someone assigned to it. You should also verify that the IP address for the printer is populated for the logged in user under settings in the app.