EDIT: After lots of help and not having a clue what\'s going on, it worked using a different method of opening (see @JohnMuggin\'s help below)--so I un-
And at the very last try this little sub. If it doesn't open your workbook then there is a problem with the path or filename
Sub opendfghj()
Dim wb As Workbook
Workbooks.Open Filename:="C:\Users\User\Desktop\Templates and Example data\Repeat Tests\file.xlsx"
Set wb = ActiveWorkbook
wb.Worksheets("Sheet1").Range("A1") = "It Works"
End Sub