Avrdude Can't open device Acess is denied

Development Tools IDE 1.x
1

`Sketch uses 2878 bytes (8%) of program storage space. Maximum is 32256 bytes.
Global variables use 220 bytes (10%) of dynamic memory, leaving 1828 bytes for local variables. Maximum is 2048 bytes.
avrdude: ser_open(): can't open device "\.\COM256": Access is denied.

Failed uploading: uploading error: exit status 1`

I have tried a lot to correct this and it still is being a persistent problem I am using an Arduino Uno and am on Windows 10. On computer start up I can get one upload but after that this error appears. I've tried unplugging my Bluetooth, checking to see if the port was being used by another application, changing the port used in device manager, restarting my computer, running Arduino in administrator mode, resetting the board, unplugging the USB from the Arduino or the Desktop, updating the driver, selecting the port and board again and Plugging into a different USB port on my Desktop. There is probably one or two more attempts that I forgot about but I think this covers it so any help would be very appreciated.

2

Which windows version?
Which IDE version?

Have you tried to temporarily disable your antivirus?

COM256 is sky-high and the maximum number. Did Windows assign it or did you hack it in device manager?

3

One of the solutions I tried was to update from 2.0 to 2.0.1 in IDE but that didn’t work. I also tried disabling windows defender and allowed IDE to communicate on private and public networks as well. My windows is 21H2 specifically (KB5019959). I also manually adjusted it to be COM 256 to make sure that there was no other program using the port.

4

Did you close serial monitor?

Maybe IDE 1.8.19 will work better for you.