How can i open or fix a file that currently wont open and has SAXParseException error message come up?

Edited a docx file for a funding application and now it wont open and comes up with SAXParseException: '[word/document.xml line 2]: Attribute w:hAnsiTheme redefined
', Stream ‘word/document.xml’, Line 2, Column 86210(row,col).
Anyone able to help how i can save the info within the document?

Thanks

If you are familiar with XML and using and XML editor providing an XML syntax checker, you could extract the ZIP container (i.e. the .docx) and evaluate and fix the failing xml file word/document.xml. If this is beyond your expertise, you may upload your failing document for someone to perform the required actions for you.