In order to fix the problem you need to reinstall FWCH67TL_CD08M4 .This can be done tricking the updater swapping the file during the update .
Go to the temp directory on the C:\Users\Your-Username\AppData\Local\Temp, you should find a Epson directory run the FWCH67TL_CD08M4.exe, now on the temp directory above you will find a directory called Firmware Updater() copy the file FWCH67TL in a safe place (this is the firmware you want).
Close the updater now run FWCH67TL_CD17M6.exe you will find in the Temp directory a new Firmware Updater() directory swap the file FWCH67T to the file you have previously saved continue the update overriding the firmware on the printer.
This should work for any other updated firmware.