Access Denied: COM3

[dennisai]

Hi, I am using Serial Port Stream on .NET 4.5.1 / Windows 10 Pro x64 as a replacement for the default SerialPort implementation in the .NET Framework. However, when I go to open my port, I get an access denied exception.

 public bool IsConnected
 {
     get {
         if (!isConnected.HasValue) {
            mutex.WaitOne();
            if (!serialPortStream.IsOpen) { serialPortStream.Open(); } // Exception thrown here.
            ...
         }
    }
}

The stack trace is as follows.

 at RJCP.IO.Ports.Native.WinNativeSerial.WinIOError() in c:\Users\jcurl\Documents\Programming\HELIOS\serialportstream\code\Native\WinNativeSerial.cs:line 937
 at RJCP.IO.Ports.Native.WinNativeSerial.Open() in c:\Users\jcurl\Documents\Programming\HELIOS\serialportstream\code\Native\WinNativeSerial.cs:line 845
 at RJCP.IO.Ports.SerialPortStream.Open(Boolean setCommState) in c:\Users\jcurl\Documents\Programming\HELIOS\serialportstream\code\SerialPortStream.cs:line 245

Any idea why this might be happening? The implementation I was using before with the SerialPort from .NET Framework was working fine, and I can open the port using Advanced Serial Port Monitor with no problems.

This is the serial port in Device Manager.

[dennisai]

Just to report, I have tried to upgrade to .NET 4.6.2 but to no avail. Same problem.

[dennisai]

Nevermind, this issue came from something else in my code. Everything works great, and way better than the default SerialPort implementation!