upload .docx file to demo, error: TypeError: Cannot convert undefined or null to object

[En777]

Uncaught (in promise) TypeError: Cannot convert undefined or null to object
at Function.assign ()
at _class._init (officeDocument.js:16:16)
at _class._init (officeDocument.js:6:3)
at _class.Part (part.js:31:8)
at _class (officeDocument.js:2:1)
at new _class (officeDocument.js:2:1)
at _class (document.js:9:23)
at new _class (document.js:2:1)
at parse (document.js:177:14)
at reader.onload (document.js:194:6)

[En777]

same error as VolodymyrBaydalka/docxjs#58

I fix it at my fork , maybe it not best
En777/docxjs-word-preview@9eed2db

and my npm package
https://www.npmjs.com/package/docx-preview-lib