"KeyError: '_winzip_' fwtool returned -1" when attempting to unpack firmware

[RobotToaster]

When trying to unpack a Sony A7 firmware on windows 10 I get the following error:

PS C:\Users\xxxx\Documents\sonytest> .\fwtool-v1.2-win.exe unpack -f Update_ILCE7V320.exe -o outDir
Extracting installer binary
Traceback (most recent call last):
  File "<string>", line 297, in <module>
  File "<string>", line 285, in main
  File "<string>", line 162, in unpackCommand
  File "<string>", line 94, in unpackInstaller
KeyError: '_winzip_'
fwtool returned -1

Is this a bug? or is there something I can do to fix this?

[DukeTomlist]

I also encountered such a problem. I think fwtool is not able to handle .exe file format.
However, you can unpack the firmware as bellow:

1. Use the Telnet and dump the firmware to the SD card (android 4 for example):
   dd if=/dev/nflasha of=/android/storage/sdcard0/DUMP.DAT bs=1M
2. Use the fwtool to unpack the .dat file:
   fwtool unpack -f XXX.dat -o outDir

Hoping this will be helpful to you

[nixcamic]

Or download the macOS updater, open it in 7-zip to: Update_ILCE7V320.dmg\Update_ILCE7V320\FirmwareUpdater.app\Contents\Resources and extract the file FirmwareData_ILCE7V320.dat then run fwtool on that.