Excel 2016 Email VBA not working

I have some code, see below, that I have been using for 6-7 months in Excel 2010 to generate an email and add pdf attachments. My company switched to 2016 recently and the code stopped working, but I cannot figure out why --neither can IT or my peers. I do not have the most advance vba skills and would appreciate any advice given. The code runs all the way through in 2016, even when you go step by step, but does not generate an email to review. The ** part near the bottom is where I think something is going on, because when I comment that part out then the email will pop up--but without the additional pdf's attached. I opened the immediate window and name21 and attach21 populate correctly.

Sub Email23()
Dim path21, date21, body21, to21, cc21, attach21, name21 As String
Dim xOutlook As Object
Dim xMailItem As Object
Dim xRg As Range
Dim xCell As Range
Dim xEmailAddr As String
Dim xTxt As String
On Error Resume Next
date21 = Month(Sheets("Data Entry Team").Range("C10").Value) & "_" & Year(Sheets("Data Entry Team").Range("C10").Value)
path21 = "(folderpath removed in example)" & date21 & "\" & "Data Entry Team - " & date21 & ".pdf"
body21 = Sheets("Named Tables").Range("AA7").Value

'to21
i = 0
For Each cell In Sheets("Named Tables").Range("U7:U11")
If InStr(Sheets("Named Tables").Range("U7").Offset(i, 0).Value, "@") > 0 Then
to21 = to21 & ";" & Sheets("Named Tables").Range("U7").Offset(i, 0).Value
End If
i = i + 1
Next cell

'cc21
i = 0
For Each cell1 In Sheets("Named Tables").Range("Y7:Y15")
If InStr(Sheets("Named Tables").Range("Y7").Offset(i, 0).Value, "@") > 0 Then
cc21 = cc21 & ";" & Sheets("Named Tables").Range("Y7").Offset(i, 0).Value
End If
i = i + 1
Next cell1

xTxt = ActiveWindow.RangeSelection.Address

'Unique code below for the email
Set xOutlook = CreateObject("Outlook.Application")
Set xMailItem = xOutlook.CreateItem(0)

With xMailItem
    .To = to21
    .CC = cc21
    .Subject = "Subject"
    .body = body21 & vbNewLine & Signature
    .Attachments.Add path21
        **i = 0
        For Each attach1 In Sheets("Named Tables").Range("U12:U30")
        name21 = Sheets("Named Tables").Range("U12").Offset(i, 0).Value
        'Debug.Print name21
        attach21 = "(folderpath removed in example)" & date21 & "\Month in Review - " & name21 & ".pdf"
        'Debug.Print attach21
        .Attachments.Add attach21
        i = i + 1
        Next attach1**
    .display
End With

Set xOutlook = Nothing
Set xMailItem = Nothing

End Sub