Invalid opcode 0xffff at address 0x003322

I use FreeRTOS to produce a robot (mavrix). I use a ATMEGA128 and AVR Studio 4.12rc1 I created a small very simple demonstration to play of the music. In the task which plays the music, the call with xTaskGetTickCount starts an error of AVRSTUDIO: AVR Simulator: Invalid opcode 0xffff at address 0x003322 I suspect a overflow of pile (Richard put 112233 at the end of the stack) but even by increasing the size of that does not change anything. If you have an idea, I am interested… Thank you.

Invalid opcode 0xffff at address 0x003322

Very likely a stack overflow.  Can you look in the stack when the error occurs?  You should be able to do this from within AVRStudio when the probelm happens.