Instead of cussing over Arduino...

[askernas]

.. not working when you are trying to update Marlin in your beloved M2 and spend an hour googling and trying and getting more and more frustrated..

How about not just quitting Simplify3D first, so the USB port is free instead?
That would work MUCH better..
Note to self.

//Micke, now running Marlin 1.02 with VIKI2 LCD.

[jimc]

haha i have done that myself.