Hi @hammy. Have you been using Serial Plotter? I ask because this will also result in the uploads to boards that use the FTDI FT232R chip failing with the "Access is denied." error.
Unfortunately, unlike Serial Monitor, the workaround for the fault as caused by Serial Plotter is a bit more convoluted. I'll provide instructions for the workaround:
- Close the "Serial Plotter" window.
- If the "Serial Monitor" view is not already open, select Tools > Serial Monitor from the Arduino IDE menus to open it.
ⓘ We must do an open/close cycle on Serial Monitor as a workaround for a bug in Serial Plotter - Click the X icon on the "Serial Monitor" tab in the bottom panel of the Arduino IDE window to close the tab:
- Upload the sketch.
- Open Serial Monitor and/or Serial Plotter again if needed after the upload is finished.
So if you were using Serial Plotter, then give that a try and let us know whether you are then able to upload.
If you weren't using Serial Plotter, or if the upload still fails even after performing that workaround, let us know and we'll investigate further.