zebra printers

ZQ610 Firmware Update Throws Language Unknown Exception


I have downloaded firmware V85.20.20Z from zebra site and I am trying to update firmware on my printer. entire file is successfully downloaded to printer after that it throws Language Unknown Exception. I am testing it from android device. Here is my environment details

Printer : Zebra ZQ610
Current Firmware Version : V85.20.19Z
Exception : com.zebra.sdk.printer.ZebraPrinterLanguageUnknownException

Here is my code which is I am using for update,

[Android] Increasing Label Darkness with ZD420: can't find ZebraPrinterLinkOs


I'm trying to increase the sharpness & darkness of shipping labels printed with my ZD420 printer via an Android app.

I found sample code for this in the docs here (http://techdocs.zebra.com/link-os/2-14/android/) but when I try it, my code crashes when I call ZebraPrinterFactory.getLinkOsPrinter(connection). The error I get is:

"java.lang.NoClassDefFoundError: Failed resolution of: Lcom/fasterxml/jackson/databind/ObjectMapper;"