void foo(int a,int b)
{

    static volatile int tmp = 0;

    struct net_buf_simple *msg1 = NET_BUF_SIMPLE(10);

    struct bt_mesh_msg_ctx ctx1 = {
        .net_idx = b,
        .app_idx = a,
        .addr = 0xFFFE,            // <------------------------------------------------------------------Group Address of all Relay
        .send_ttl = BT_MESH_TTL_DEFAULT,
    };

    
    bt_mesh_model_msg_init(msg1, BT_MESH_MODEL_OP_2(0x82, 0x03));

    net_buf_simple_add_u8(msg1,tmp);
    net_buf_simple_add_u8(msg1,0x00);
    net_buf_simple_add_u8(msg1,0x00);
    net_buf_simple_add_u8(msg1,0x00);

    if (bt_mesh_model_send(&root_models[2], &ctx1, msg1, NULL, NULL))

    {
        printk("Unable to send Vendor Button message\n");
    }

    printk("Button message sent with OpCode 0x%08x\n", BT_MESH_MODEL_OP_2(0x82, 0x03));

    tmp++;

}

I am trying to execute above function foo() from Button interrupt on nRF52840_PCA10056.

And getting error As attached in image.

My intention is to send value of tmp variable to all nodes in the Group. Could you please help me to solve

this error ?