Had to remove the +universe and set the MAC ID address statically to be able to communicate to the rf minimalist shield.
Change from:
static uint8_t mac[] = { 0x12, 0x34, 0x56, 0x00, 0x00, 0x00 + universe};
To:
static uint8_t mac[] = { 0x12, 0x34, 0x56, 0x00, 0x00, 0x01};