SAXParseException: '[word/document.xml line 2]: Attribute w:cstheme redefined ', Stream 'word/document.xml'

My document won’t open anymore, error:

SAXParseException: ‘[word/document.xml line 2]: Attribute w:cstheme redefined’, Stream ‘word/document.xml’, Line 2, Column 137765

The document was created in libreoffice word and opened and closed several times without any problem untill this error message showed up. It was not opened in any other text editor.
How can i open it again and how can i prevent this error to happen again?

Thanks and brgds,

Uzz

Search the forum with saxparse

Thanks, should have done that first…