File type plug-in for Trados Studio 2017


I created a file type plug-in for word file(doc, docx, docm).

When I run on Trados Studio 2017, "doc " type is OK, but "docx" and "docm" failed.

They are recognized as Word 2007-2019 file.

I found that the function BuildFileSniffer(string name)  is not called.

My PC is windows10, and I used visual studio 2017 .

The file types I created have higher priority than Word 2007-2019 file type.

Can anyone suggest where problem may be?

Thank you.