There are serious error:

System. IO. Ports. WinSerialStream. ReportIOError (System. String optional_arg) (at & lt; 0079 a30f96a047348857e1cecc6c638a & gt; : 0)
System. IO. Ports. WinSerialStream.. Ctor (System. String port_name, System. Int32 baud_rate, System. Int32 data_bits, System. IO, Ports, Parity, Parity, System. IO, Ports, StopBits sb, System. Boolean dtr_enable, System. Boolean rts_enable, System. IO, Ports, Handshake, hs System. Int32 read_timeout, System. Int32 write_timeout, System. Int32 read_buffer_size, System. Int32 write_buffer_size) (at & lt; 0079 a30f96a047348857e1cecc6c638a & gt; : 0)
(wrapper remoting invoke - with - check) System. IO. Ports. WinSerialStream.. Ctor (string, int, int, System. IO, Ports, Parity, System. IO, Ports, StopBits, Boolean, Boolean, System. IO, Ports, Handshake, int, int, int, int)
. System. IO Ports. SerialPort. The Open (), the at & lt; 0079 a30f96a047348857e1cecc6c638a & gt; : 0)

Is the IO mouth refused to visit, multiple scripts at the same time, please read a port is not feasible?