Oracle Error Codes

cannot reach the database

The broker rejected an operation requested by the client when the database required to execute that operation was not reachable from the database where the request was made. If the request modifies the configuration, the request must be processed by the copy of the broker running on an instance of the primary database.

How to Solve :

Check your network connections between all of the databases in the configuration. Alternatively, you can connect your client to a different database in the Data Guard broker configuration and try your request again. If you are simply attempting to determine the status of a particular database in the configuration, you may connect your client to that database and get the current value of the StatusReport property for that database.