GlossaryDocumentPart is null

I was wondering about how to add Building Blocks through OpenXML SDK.

After messing around with it a little I noticed that when I added Building Blocks to .dotx info about them went into word\glossary\document part of the file so I decided to add some info there.

However when I try ussing this line

document.MainDocumentPart.GlossaryDocumentPart.GlossaryDocument.DocParts.AppendChild<DocPart>(part);

I always get a null reference on GlossaryDocumentPart. When I check the underlying XML there is a glossary folder with 5 .xml files.

Is this GlossaryDocumentPart not the right thing?

OK please ignore this, it was a mistake on my behalf.

The path to the dotx file was wrong but I didn't get an exception on the document open method because there existed a file in the debug folder (wich didn't have a glossary part).

On another note, does the sequence of w:tags matter?