Interop.Word Documents.Open is null

If you are still looking for the answer I have found it just a moment ago for my project.

Open DCOM Config Settings:

    Start -> dcomcnfg.exe
    Computer
    Local Computer
    Config DCOM
    Search for Microsoft Word 97-2003 Documents -> Properties

Tab Identity, change from Launching User to Interactive User

Interop.Word Documents.Open is null

https://support.microsoft.com/en-us/kb/176799

http://forums.asp.net/t/1232621.aspx?Interop+Word+Document+Add+returning+null

http://forums.asp.net/t/1902899.aspx?Cannot+open+a+Word+doc