4.13 is the latest firmware for the Everest 600, firmware version 4.20 is a deprecated version that should be updated to 4.13.
This firmware can be loaded on autoloaders or AutoPrinters using an Everest 600 printer or a stand-alone Everest 600 printer.
The Everest600Updater.exe is a universal firmware updating tool for use with the Everest 600 and Everest Encore printers. The updater looks at the control board version or printer model number, and automatically applies the correct firmware (all firmware versions are embedded in the application).
NOTE: Printers with firmware version 4.07 should not update to 4.13. Version 4.07 has the V1 update algorithm and should not be updated to later versions. Printers with version 4.08, and higher, are safe to update to version 4.13.
If you are experiencing a the issue of 4 flashing lights on your printer, you will need to update the firmware manually. Please see the article linked below:
https://support.rimage.com/hc/en-us/articles/360035529151-Everest-600-Recover-from-4-flashing-lights
This firmware was released July 2021.