Star Transit .ppf Files Do Not Open After Dowloading Plugin

Hello everyone. 

I have downloaded the Star Transit Plugin but I am still unable to open any Transit files (windows 10 and Trados 2021)

I am following this guideline '''' but when I try to open a .ppf file from the Star Transit Menu, the file or package won't open. I have tried with the correct language combination but still unable to open the file. 

Would anybody please help me?

Thanks in advance.