Weird black rectangle in Word's headings

Solution 1:

Here is a short macro to repair this from Word MVP Doug Robbins:

Sub FixNumberingIssuesInLists()
'Macro originally created by MVP Doug Robbins
'Modified by MVP Stefan Blom, February 2020
Dim LT As ListTemplate
Dim i As ListLevel
For Each LT In ActiveDocument.ListTemplates
    For Each i In LT.ListLevels
        If i.NumberStyle <> wdListNumberStyleBullet Then
            i.Font.Reset
        End If
    Next i
Next LT
End Sub

I tried it with your sample and it works fine.

Microsoft Community Answers

• Using macros by Greg Maxey
• Installing macros from forums by Graham Mayor