Excel 2016 Macro Unable to Find File : Runtime Error 1004 - vba

Question

I am running into issues while attempting to open an additional Excel file using VBA in Excel 2016. It matters not whether the file is in the same directory. I am thinking it has something to do with a default setting in Excel 2016 that is blocking the search? The Macro functioned in Excel 2010.
Private Sub CommmandButton_Click()
Dim source As String
Dim temp As Workbook
source = InputBox("Enter source")
Set temp = Workbooks.Open(source)
end sub

Answer 1

Here is an example solution using the FileDialog object
Private Sub CommmandButton_Click()
Dim fDialog As FileDialog, _
wb As Excel.Workbook
Set fDialog = Application.FileDialog(msoFileDialogFilePicker)
With fDialog
.AllowMultiSelect = False
.Title = "Select a file"
.InitialFileName = "C:\"
.Filters.Clear
' Prevent Error by specifying that the user must use an excel file
.Filters.Add "Excel files", "*.xlsx,*.xls,*.xlsm"
End With
If fDialog.Show = -1 Then
Set wb = Excel.Workbooks.Open(fDialog.SelectedItems(1))
Else
End ' Cleanly exit the Macro if the user cancels
End If
End Sub

Answer 2

You are allowing users to do more than point and click. This is asking for trouble. Instead:
Private Sub CommmandButton_Click()
Dim source As String
Dim temp As Workbook
source = Application.GetOpenFilename()
Set temp = Workbooks.Open(source)
end sub
This code can be further enhanced to:
1. pre-select the initial path
2. set the file-type(s)
3. give guidance
4. gracefully handle cancellations