16620, 0000, "one or more databases could not be reached for a delete operation"
*Cause: One or more standby databases could not be reached for either
a DGMGRL CLI REMOVE DATABASE or a REMOVE CONFIGURATION command.
*Action: This typically indicates a network problem where the standby
database is unable to respond to the primary database. In the
event of this situation, examine the primary database Data
Guard broker log to determine which standby databases could
not be reached. For each standby database not reached,
connect to that database and shut down the broker by setting the
initialization parameter, DG_BROKER_START, to false. After the
broker has been shut down for the standby database, locate the
Data Guard broker configuration files from the standby database
DG_BROKER_CONFIG_FILE[1|2] initialization parameter values and
delete them. Then restart the broker by setting DG_BROKER_START to