Run time error (Err=9) when saving file using saveas

[welchs101]

I have the following file designed to save a file. I have NO idea why this occurring but i get a run time err #9.

Any ideas?

Sub save_combined_file(fl_combined As String, ws_combined As String, _
                            pth_save As String, save_error As Boolean)

'Dim New_file_name1 As String
Dim fl_new_combined As String

'create file name with EXTENSION
fl_new_combined = "Combined_Comment_File" + ".xlsx"

'**Start:***save file
'turn display prompts off
Application.DisplayAlerts = False

'note:  pth_save should have "\" as the last character instring
New_file_name1 = pth_save & fl_new_combined

'if file to be saved is already open then close it
'If AlreadyOpen(fl_new_combined) Then Workbooks(fl_new_combined).Close


On Error Resume Next

save_error = False

Workbooks(fl_combined).Worksheets(1).Activate


'save file:  FileFormat = 51 = xlOpenXMLWorkbook which means the extension will be ".xlsx"
'Workbooks(fl_combined).SaveAs FileName:=New_file_name1, FileFormat:=51, CreateBackup:=False
ActiveWorkbook.SaveAs FileName:=New_file_name1, FileFormat:=51, CreateBackup:=False

'if there is an error saving the file then alert user and stop the program
If Err <> 0 Then

    MsgBox (Err.Number)
    
    save_error = True

    If Err.Number = 1004 And Len(New_file_name1) > max_file_name_path Then
        MsgBox ("Error saving file.   The file name + directory-path is larger than " & max_file_name_path & ".  Program will now end.")
    Else
        MsgBox ("There was an error saving the file.  The program will now stop.")
    End If

    Application.DisplayAlerts = False
    Err.Clear
    On Error GoTo 0
    'turn back on display prompts
    Application.DisplayAlerts = True
    Exit Sub

End If

On Error GoTo 0

'turn back on display prompts
Application.DisplayAlerts = True

'the consolidated file has a new file name
fl_combined = fl_new_combined

MsgBox ("jlkjl")

'close the combined file.
If AlreadyOpen(fl_combined) Then Workbooks(fl_combined).Close

End Sub