task que hanging problem

Hi.

/*
 * ======== main ========
 */
void main() {

    LOG_printf(&trace,"Start of semaphore. \n");
    printf("Preview Application\n");
    fflush(stdout);
    return;
}

void initTSK()   // Priority 15.
{                                                  
  
    // Init queue.
                                                                  
}

void uartTSK(void) // Priority 1.
{
   while(1)
   {
 msg = QUE_get(&freequeue); 
 // DO something with msg.
 QUE_put(&queue,msg);
 SEM_post(&sem);
   }   
}
 
 
void SomeTask(void)  // Priority 2.
{

   // Some commands that uses interrupt or dma.
   while(1)
   {
 SEM_pend(&sem,SYS_FOREVER);
 if(QUE_empty(&queue))
 {
  LOG_printf(&trace,"Empty free queue!\n");
  SYS_abort("Empty free queue!\n");
 }
 msg = QUE_get(&queue);
 // Here some manipulation with msg.
 QUE_put(&freequeue,msg);
   }
}

This programm works fine , It switches between 2 tasks and moves data  from void uartTSK(void) to void SomeTask(void)  .

However if I enable the line // Some commands that uses interrupt or dma.

in void SomeTask(void) , then the programm is stuck.

Please Advise.