Receive Error 1004 while running section of Code Selection.copy, - excel

Question

Heading ## I was able to get the selection to select active Cell a1 but now receive error 1004 Application Object-defined error, AT THE SECTION OF CODE <Sheets.Add before:=Workbooks(myFile).Sheets("Make DMS Report")>
Please see the code below.
The code filters the data from Agile export and filters the product Part number and associates the manufacture part number with the part.
'Start code
<Sub ImportAgileBOM()
'GoTo test1
Dim FullFileName As String
Dim myFile As String
Dim FileFormat As String
Dim rng As Range
'Open .cvs worksheet and convert to text format.
myFile = ActiveWorkbook.Name
FullFileName = Application.GetOpenFilename("Text files , *.csv; *.txt,Excel files (*.xls*), *.xls*", 2, "Select Agile Mfr BOM Report", , False)
If FullFileName = "False" Then
Application.DisplayAlerts = True
End
End If
'This section converts the .cvs and renames workboot to text
If Right(FullFileName, 4) = ".csv" Or Right(FullFileName, 4) = ".txt" Then
FileCopy FullFileName, FullFileName & "importtemp.txt"
FileFormat = "Text"
Workbooks.OpenText Filename:=FullFileName & "importtemp.txt", _
DataType:=xlDelimited, ConsecutiveDelimiter:=False, _
Tab:=False, Semicolon:=False, _
Comma:=True, Space:=False, Other:=False, _
FieldInfo:=Array(Array(1, 2), Array(2, 2), Array(3, 2), Array(4, 2), Array(5, 2), Array(6, 2), Array(7, 2), Array(8, 2))
Else
FileFormat = "Excel"
Workbooks.Open Filename:=FullFileName
End If
'Make Active Range
Set rng = ActiveSheet.Range("A1")
'Range("A1").Activate
If FileFormat = "Text" Then
If ActiveCell <> "Manufacturer BOM Report" Then
MsgBox "Input file not in Manufacturer BOM Report format"
ActiveWindow.Close
Application.DisplayAlerts = True
End
End If
ElseIf ActiveCell.Offset(0, 1) <> "Manufacturer BOM Report" Then
MsgBox "Input file not in Manufacturer BOM Report format"
ActiveWindow.Close
Application.DisplayAlerts = True
End
End If
'FullFileName = ActiveWorkbook.Name
'Sheets(ActiveSheet.Name).Copy Sheets.Add Sheet.before:=Workbooks(myFile).Sheets("Make DMS Report")
'Windows(FullFileName).Activate
'ActiveWindow.Close savechanges:=False
'Copy data to secound sheet
FullFileName = ActiveWorkbook.Name
Cells.Select
Selection.Copy
Workbooks(myFile).Activate
Sheets.Add before:=Workbooks(myFile).Sheets("Make DMS Report")
ActiveSheet.Paste>
'I receive the error when trying to add the created sheet to the Active sheet.
If you could assist in this issue it would be appreciated

Answer 1

I am now receiving an error at <Range("A1"). select> the error message is Run-time error 1004 Application-defined Or Object-defined error, I don't understand why I am receiving this error, just selecting a cell