Detecting Errors in Conditional Formatting Formulas

The Tip's FindCorruptConditionalFormat macro might be more reliable if the following statement
    Selection.SpecialCells(xlCellTypeAllFormatConditions).Select
was replaced by this statement
    ActiveSheet.UsedRange.SpecialCells(xlCellTypeAllFormatConditions).Select
But here is a more efficient version of the macro:

Sub FindCorruptConditionalFormat2()
    Dim fc As FormatCondition
    ActiveSheet.UsedRange.SpecialCells(xlCellTypeAllFormatConditions).Select
    For Each fc In Selection.FormatConditions
        If InStr(1, fc.Formula1, "#REF!", vbBinaryCompare) > 0 Then
            MsgBox fc.AppliesTo.Address & ": " & fc.Formula1
        End If
    Next fc
End Sub

Notice Microsoft's documentation defines xlCellTypeAllFormatConditions as "Cells of any format," but testing demonstrates it actually selects "Cells of any conditional format."
Similarly, Microsoft's documentation defines xlCellTypeSameFormatConditions as "Cells having the same format," but it actually selects "Cells having the same conditional format." For this case the macro's first statement after Dim... should be replaced by
    If ActiveCell.FormatConditions.Count = 0 Then Exit Sub
    ActiveCell.SpecialCells(xlCellTypeSameFormatConditions).Select
Like many, I’ve been frustrated when my carefully crafted conditional formatting becomes corrupted after innocently performing a copy/paste or some other such sin. And Excel’s miserable Conditional Formatting Rules Manager makes it a chore to fix the mangled rules. So My Excel Toolbox includes macros to backup and restore the active sheet’s conditional formatting using named ranges that auto-adjust to row/column changes. Run the CFBackup macro before your conditional formatting rules are broken. If they later become broken, run CFRestore.
My Excel Toolbox also includes the following dynamic array function:
    =ListFormatConditions([AllSheets], [SkipHeader])
This function returns Applies To Range, Type, and Stop If True for each conditional format. When using pre-2021 versions of Excel without support for dynamic arrays, review the PDF file UseSpillArray.pdf.
See https://sites.google.com/view/MyExcelToolbox/