Set c = .Find("Уведомление", LookIn:=xlValues)

(438) Object doesn't support this property or method

Dim XL As Object 'Excel.Application
Dim WB As Object 'Excel.Workbook
Dim SH As Object 'Excel.Worksheet
Dim c As Object
Dim cRng As Object
  Set XL = CreateObject("Excel.Application")
  Set WB = XL.Workbooks.Open(ImaFile)
    
  Set SH = WB.Worksheets(1)
  'Set SH = WB.activeSheet
  
  With SH
  
    lLastRow = .Cells.SpecialCells(xlLastCell).Row
    lLastCol = .Cells.SpecialCells(xlLastCell).Column
  
  '----------- если документ не Уведомление - выходим
    Set c = .Find("Уведомление", LookIn:=xlValues) 'ОШИБКА
    
    If c Is Nothing Then
      Debug.Print "Документ не уведомление"
      GoTo lbl_exit
    End If

With .range(.Cells(1, 1), .Cells(lLastRow, lLastCol))
...
end with