Compile error: User-defined type not defined

[misterbobthetomato]

VBA script not functioning when pasted into Outlook (2013) on another PC within the same network. The only thing I am seeing is how the icon is labeled on the ribbon so, perhaps, I didn't complete the entire set-up properly?
Thanks so much.
Bob

Current, functioning version - Labeled as "OutlookVBA.ThisOutlookSession.OpenLinksMessage"

Private Declare Function ShellExecute _
Lib "shell32.dll" Alias "ShellExecuteA" ( _
ByVal hWnd As Long, _
ByVal Operation As String, _
ByVal Filename As String, _
Optional ByVal Parameters As String, _
Optional ByVal Directory As String, _
Optional ByVal WindowStyle As Long = vbMinimizedFocus _
) As Long

Sub OpenLinksMessage()
Dim olMail As Outlook.MailItem
Dim Reg1 As RegExp
Dim M1 As MatchCollection
Dim M As Match
Dim strURL As String
Dim lSuccess As Long

Set olMail = Application.ActiveExplorer().Selection(1)

Set Reg1 = New RegExp

With Reg1
.Pattern = "(https?[:]//([0-9a-z=\?:/\.&-^!#$%;_])*)"
.Global = True
.IgnoreCase = True
End With

If Reg1.Test(olMail.Body) Then

Set M1 = Reg1.Execute(olMail.Body)
For Each M In M1
strURL = M.SubMatches(0)
Debug.Print strURL
If InStr(strURL, "unsubscribe") Then GoTo NextURL
If Right(strURL, 1) = ">" Then strURL = Left(strURL, Len(strURL) - 1)

lSuccess = ShellExecute(0, "Open", strURL)
DoEvents

NextURL:
Next
End If

Set Reg1 = Nothing
End Sub

New, non-functioning version - Labeled as "Project1.ThisOutlookSession.OpenLinksMessage"
Yielding this error message - "Compile error: User-defined type not defined"

Private Declare Function ShellExecute _
Lib "shell32.dll" Alias "ShellExecuteA" ( _
ByVal hWnd As Long, _
ByVal Operation As String, _
ByVal Filename As String, _
Optional ByVal Parameters As String, _
Optional ByVal Directory As String, _
Optional ByVal WindowStyle As Long = vbMinimizedFocus _
) As Long

Sub OpenLinksMessage()
Dim olMail As Outlook.MailItem
Dim Reg1 As RegExp
Dim M1 As MatchCollection
Dim M As Match
Dim strURL As String
Dim lSuccess As Long

Set olMail = Application.ActiveExplorer().Selection(1)

Set Reg1 = New RegExp

With Reg1
.Pattern = "(https?[:]//([0-9a-z=\?:/\.&-^!#$%;_])*)"
.Global = True
.IgnoreCase = True
End With

If Reg1.Test(olMail.Body) Then

Set M1 = Reg1.Execute(olMail.Body)
For Each M In M1
strURL = M.SubMatches(0)
Debug.Print strURL
If InStr(strURL, "unsubscribe") Then GoTo NextURL
If Right(strURL, 1) = ">" Then strURL = Left(strURL, Len(strURL) - 1)

lSuccess = ShellExecute(0, "Open", strURL)
DoEvents

NextURL:
Next
End If

Set Reg1 = Nothing
End Sub