I found my own solution.
instead of
cmd = New SqlCommand("update setbool set pos_val='False',valid_rp='False',Pos_save='False'", conn)
cmd.ExecuteNonQuery()
Return Nothing
i changed
Using cmd1 As New SqlCommand("update setbool set pos_val='False',valid_rp='False',Pos_save='False'")
cmd1.CommandType = CommandType.Text
cmd1.Connection = conn
conn.Open()
cmd1.ExecuteNonQuery()
conn.Close()
End Using
Return Nothing