Connection failure after multiple connect/disconnect cycles.

[borisw37]

Can't connect to device after numerous connect / disconnect cycles.
Windows 10
Python 3.8
Pygatt 4.0.5
Dongle BLED112

Code:

import pygatt
import time

def connect_show_devices():
    adapter_timeout = 5
    adapter = None
    try:
        adapter = pygatt.BGAPIBackend()
        adapter.start()
    except:
        print("FAILURE")
    if adapter:
        devices = adapter.scan(run_as_root=True, timeout=adapter_timeout)
        print(f"SCAN COMPLETE {adapter_timeout}s:")
        print("SCAN FOUND:")
        for device in devices:
            print(f'Name:{device["name"]}, Address:{device["address"]}')
        adapter.stop()
    return

if __name__=='__main__':
    i = 0
    for i in range (300):
        print(f"Iteration: {i}")
        connect_show_devices()
        time.sleep(1)

Error

INFO:pygatt.backends.bgapi.bgapi:Auto-detecting serial port for BLED112
DEBUG:pygatt.backends.bgapi.util:Found 1 serial USB devices
DEBUG:pygatt.backends.bgapi.util:Checking serial USB device: COM3 - Bluegiga Bluetooth Low Energy (COM3)
DEBUG:pygatt.backends.bgapi.util:USB device: Bluegiga Bluetooth Low Energy (COM3) VID=0x2458 PID=0x0001 on COM3
INFO:pygatt.backends.bgapi.bgapi:Found BLED112 on serial port COM3
DEBUG:pygatt.backends.bgapi.bgapi:Failed to open serial port
Traceback (most recent call last):
  File "C:\code\64bit\venv2\lib\site-packages\pygatt\backends\bgapi\bgapi.py", line 174, in _open_serial_port
    self._ser = serial.Serial(serial_port, baudrate=115200,
  File "C:\code\64bit\venv2\lib\site-packages\serial\serialwin32.py", line 31, in __init__
    super(Serial, self).__init__(*args, **kwargs)
  File "C:\code\64bit\venv2\lib\site-packages\serial\serialutil.py", line 240, in __init__
    self.open()
  File "C:\code\64bit\venv2\lib\site-packages\serial\serialwin32.py", line 62, in open
    raise SerialException("could not open port {!r}: {!r}".format(self.portstr, ctypes.WinError()))
serial.serialutil.SerialException: could not open port 'COM3': FileNotFoundError(2, 'The system cannot find the file specified.', None, 2)
WARNING:pygatt.backends.bgapi.bgapi:Unexpectedly not connected to USB device
Traceback (most recent call last):
  File "C:/code/64bit/test_BLED112_failure.py", line 45, in <module>
    connect_show_devices()
  File "C:/code/64bit/test_BLED112_failure.py", line 37, in connect_show_devices
    scan_bt(adapter, adapter_timeout)
  File "C:/code/64bit/test_BLED112_failure.py", line 18, in scan_bt
    devices = adapter.scan(run_as_root=True, timeout=adapter_timeout)
  File "C:\code\64bit\venv2\lib\site-packages\pygatt\backends\bgapi\bgapi.py", line 340, in scan
    self.send_command(
  File "C:\code\64bit\venv2\lib\site-packages\pygatt\backends\bgapi\bgapi.py", line 283, in send_command
    raise NotConnectedError()
pygatt.exceptions.NotConnectedError

Current resolution
Go to device manager, find the Bluegiga device (with failure exclamation icon). Disable / re-enable the device.

Device status in device manager

This device cannot start. (Code 10)

{Operation Failed}
The requested operation was unsuccessful.

[peplin]

The error message is interesting:

The system cannot find the file specified

When this happens, has the BLED device been detected under a new name?