IAR Workbench compiler

Dear friends,

I want to program my Arduino Mega 2560 using the “IAR Embedded Workbench for Atmel AVR”. First I wanted to download a simple program but I have problems with the compiling/debugging process, it says “failed to initialize USB driver” then “the debug session could not be started”. I used the IAR before with other uC-s, and it worked fine, now with the AVR version my main problem is, that I don’t really know which debugger I should choose (AVR ONE!, CCR, ICE200, etc,) and how to configure it. Could you please help me to solve this ?

Could you please help me to solve this ?

How is this an Arduino problem?