Failed cluster and "proxy timeout"

We had 2 physical SEA appliances working in cluster. The master has failed, so the secondary inherited its IP address.

I can log into that appliance GUI but each time I try to access "configuration" menu it is giving me "proxy timeout" error. Other menu items seem to work, but very slow. I suspect the secondary wants to connect to the master, which is no longer available. Is there a way I can remove cluster configuration or access configuration without GUI?