First Arduino Uno - Immediate Problems I'm new to Arduinos but researched thoroughly before buying one. Just for context I'm an IT Professional with 20 years in the game, I'm comfortable with Linux/Unix, Windows, Raspberry Pi's, electronics, hardware, software and monitoring/switching COM ports.

I've purchased my first Arduino (actually a Elegoo Uno R3 clone) and have just tried it out of the box connected to two different systems; one Windows 7 64bit Enterprise the other Kubuntu. Despite having the correct COM port selected on both I'm getting similar error messages:

**avrdude: ser_open(): can't open device "\\.\COM15": The system cannot find the file specified.**


or

**avrdude: ser_open(): can't open device "\\.\COM6": Access is denied.**

Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.


Yes I have tried different COM ports.

Yes I have tried turning off Firewalls

Yes I have tried different USB cables.

I have a solid green LED and a intermittently blinking orange LED.

The suggested Troubleshooting guide + many Forum Threads do not seem to cover this exact error I'm encountering - well they do but they tend to be people with the simple issue of them not selecting the correct COM port or having the same COM port tied up with another task. Then choose the correct port and it works. I'm confident I have the correct COM port and when I click Get Board Info it pulls down the correct board information and serial number etc.

On the Linux system I was seeing a similar behavior with slightly different wording: Permission Denied

On my Windows 7 system I run as a Standard User (as one should, not as an Administrator), but regardless I have tried running the Arduino application normally and as an Administrator user but it has the same result. And it seems strange that it encounters the same style of error across multiple different operating systems.

Have I just been really unlucky and got a dud for my first Arduino or am I missing something obvious?

Thanks for your time and help.
On Linux "Permission Denied" generally means one of two things:


You're not in the dialout group (or you haven't logged out and logged in since), or
Something else is using the serial port.


For 1:

sudo usermod -a -G dialout ashley
&lt;log out or reboot&gt;


For 2:

The most common culprit is ModemManager. The simplest cure is to uninstall it:

sudo apt-get remove modemmanager