Passport Essential won't allow unlock.exe

I recently did a firmware upgrade- after several years, to my Passport Essential 1T drive. I don’t always run WD Smartware to back up my drive, so sometimes I just park a few temporary files using unlock.exe command in the menu list. I get “This application has encountered an unexpected error and is now exiting”.

Can I uninstall the firmware upgrade to an older version?
If I can, will that have the possibility of working?

You can try to check after re-installing of updated version of WD SmartWare from below link.