Bad file name or number vba - excel

Question

my code keeps getting a bad file name or number error and I can't figure out what the issue is, any help would be appreciated! I'm trying to store the filepath based on user selection as a variable which I can reference later in a vlookup. Below is my code, I can't figure out what's wrong but I used the pasted code in another macro which compiled fine.
sub edits
dim xpath and xfile as string
xPath = NewPath 'Newpath function executes
xfile = Dir$(xPath & "*.xlsm*", vbNormal) 'error here
Set SourceBook = Workbooks.Open(xPath & xfile)
End Sub
Function NewPath() As String
With Application.FileDialog(msoFileDialogOpen)
.ButtonName = "Choose a file"
.Title = "Previous File"
.AllowMultiSelect = False
If .Show Then xPath = .SelectedItems(1) & "\"
End With
End Function
Below is the code I've used which has compiled, it has the user select a folder instead of a file
sub something
dim xpath and xfile as string
xPath = NewPath
If Not strPath = vbNullString Then
xfile = Dir$(xPath & "*.xlsm", vbNormal)
Do While Not xfile = vbNullString
'some code
Set SourceBook = Workbooks.Open(xPath & xfile)
SourceBook.Close False
xfile = Dir$()
Loop
End If
End Sub
Function NewPath() As String
With Application.FileDialog(msoFileDialogFolderPicker)
.ButtonName = "Choose a folder"
.Title = "Folder Picker"
.AllowMultiSelect = False
If .Show Then NewPath = .SelectedItems(1) & "\"
End With
End Function