Could not write to '\\.\COM16',

The error message "Could not write to '\\.\COM16'" typically occurs when there is an issue with accessing or writing to the COM port specified, in this case, COM16. Here are a few solutions you can try:

1. Check COM Port Availability: Ensure that the COM port (COM16) is available and not being used by any other application. You can try disconnecting and reconnecting the device connected to that port.

2. Administrative Access: Make sure you have administrative privileges on your computer. Some operations, such as accessing certain COM ports, may require admin rights.

3. COM Port Configuration: Verify that the correct COM port settings are configured in your software or application. Double-check the baud rate, data bits, parity, stop bits, and flow control settings.

4. Update Drivers: Update the drivers for the device connected to the COM port. Outdated or incompatible drivers can cause issues with communication.

5. Restart System: Sometimes, a simple system restart can resolve communication problems related to COM ports.

If none of the above solutions work, it's possible that there might be a hardware issue or conflict with other devices on your system. In such cases, you may need to consult a technical expert or contact the manufacturer for further assistance.