This problem is making me pull my hair out. I have a Word document with 100% English text (does not, has not, and never will have any other languages). However, when I go to insert a citation and I click the correct source from the drop-down list, I get:

[焾‡]

as opposed to:

[1]

I have tried deleting and recreating the source to no avail. Furthermore, when I delete the citation and then click "Update citations and bibliography", the next citation changes to this strange character. All of the rest of the citations are numbered correctly.

Any idea what's going on here, and how I can fix it?