DNS bad keys Event 1119

Hi,

I am a newbie of setting up window cluster and got the following error which I have no idea how to fix it. Please help

There are 2 nodes in the cluster. When I tried to do failover testing, the failover can work fine. However, I got the DNS bad key with Event ID 1119.

Can you give my any hints how to remove this error message?

Thanks for help
Benson