Pass value of Object to String

Small error that might be causing your problem:

    With Sheets("Misc data")
        'Loop thru Column F
        sh7LastRowG = .Cells(Rows.Count, "G").End(xlUp).Row
        Set sh7RangeG = .Range("G1:G" & sh7LastRowG)
    End With

    For Each sh7CellG In sh7RangeG
        If sh7CellG = sLogin Then
            Do While sLogin <> sLogin    ' ""
                MsgBox "You must enter your Intitals, initials must be approved! (Caps only!)"
                sLogin = InputBox("Enter Initials here (Caps only!)")
            Loop

            MsgBox sh7CellG.Offset(0, 1)  'for testing
            sLogin2 = sh7CellG.Offset(0,1)  <-----Offending line of code "error 424" you had sht instead of sh
            Call Button_Controls.Buttons_Enabled
        End If
    Next sh7CellG