Cluster Manager Error In Oracle Database

Hi everyone,
I am having a little problem here with my oracle database configuration. I have two clusters running. Will mention their name if someone replies to me. Problem is that when I connect to one of the clusters or even both of the nodes with it, all goes well status is displayed of the cluster etc. But if I click on the node which I am not pointing, the browser waits for a few moments and then gives the error just like in the image Unable to Detect Active Node List.
And at the same time one more error appears as Error Was Encountered in Connecting to the Oracle Database System. As a solution I tried to change password to one of the cluster as same as the ROOT password but it wont work. So can you tell me how it could be sorted out?
Thanks.
Oracle Database Configuration Assistant Alert
Cluster manager API: Unable to detect active node list.
Please verify the state of the Cluster Manager.
