Upload to Pro Mini cant open device access is denied

When I try and upload a sketch to my pro mini via my FTDI board I get an error that says
arvdud:ser_open(): can't open decice "\.\COM5": access is denied

Once in a blue moon if i restart my computer with the FTDI connected to the pro mini it will work sometimes but usually only once

The "access is denied" error happens when the port is already open in another application. Only one application can have a port open at a time. In some cases, there might be a hidden application running in the background like a Bluetooth device driver or something that assumes any port is its device and opens it. So check to see if there are any applications like that running on your computer.

Sometimes a glitch will cause a port to get stuck open and restarting the computer will fix that, but it sounds like you are having the problem even after a restart so I don't think that's the problem.

Thank you for the response, how do I tell which devices are running on each port in Windows 10?

Here's how you can do it in the Arduino IDE:

  • Unplug your Arduino board from the computer.
  • Tools > Port
  • Note the ports, if any, listed in the menu.
  • Close the Tools menu
  • Plug your Arduino board into the computer.
  • Tools > Port - The new port listed in the menu is your Arduino board.

You could do the same in Windows Device Manager if you prefer.

Thank you for the reply however it still will not work. I dont understand how to get the FTDI to work without have the access denied. If I plug in a Nano to the usb it is com4 but when I plug the ftdi into the same usb port it is com5, not sure if that helps. Also, when I looked at the windows device manage when the FTDI is plugged in it says everything is working properly and the drivers are up to date.

Also, the specific error i get in the IDE is write error:sorry no info avil then read error: access is denied

I solved my issue. I realized that i needed to connect the FTDI device to my pro mini first, then connect the usb cable to the FTDI after it is connected to the pro mini, then it recognized the device and uploads.