Cannot change language setting to eng

After install the certificate I bought from a Chinese reseller, Directory Opus automatically changed the language setting to simplified Chinese. How can I change it back to English?

I Tried:

  1. Change it in setting. But there are only two options available, simplified Chinese, or traditional Chinese.Then I googled about this problem and tried another solution in this thread :
  2. Fully exit Opus and change it via command line
"C:\Program Files\GPSoftware\Directory Opus\dopus.exe" language=english

and also failed, it first shows Converting configuration to new language. Please wait...
imagebut then , change it back to Chinese请稍等…正在应用新语言…
image

As products purchased from our Chinese resellers are heavily discounted, they are designed to only run in Chinese.

Use discounted amount to reduce the user experience of consumers, okay?
What can I do to support multiple languages?

Email sales@gpsoft.com.au if you'd like to upgrade to the multilingual version.