Hi Yodying,
Yes as a solution you can use the standard DNS query. But if you could provide the use case of non-standard DNS query (if at all it’s being used in your environment) as mentioned in trail mail that would help us in replicating it in-house. But irrespective of that, engineering is continuing with the investigation to determine were it got crashed. As mentioned before, the cause for crash is a non-standard DNS query, but we have to determine at which pointer in the netscaler code it got crashed and fix it accordingly. That’s why it’s taking some time.