Importing document fails with ToC sometimes

[adomasven]

I cannot reproduce this in a new document, but we had an user send one in: https://forums.zotero.org/discussion/119770/i-broke-switch-word-processors

Even running a VBA script that just retrieves hyperlinks in this document throws a VBA error, so something is wrong in Word's implementation or encoding of this document.

Over the past year we've had various reports of issues with ToC in Word, like causing it to crash when citing, etc, so it seems to be in part some sort of ongoing buggery on Microsoft's side.