Oracle Message NNO-00266 - cannot find document string in configuration database

ERRORcannot find document string in configuration database
CAUSEThe server encountered an error while trying to get its configuration ID from the configuration database. The error can occur any time the server is unable to access the configuration database. This error will cause the server to shut down.
ACTIONMake sure that the database is running, that its name and password as specified in the Oracle Network Manager are accurate, and that there is SQL*Net connectivity between the Oracle Names server and the database. To force the server to start up anyway, using its checkpoint data, start the server with the names.no_region_database parameter set to TRUE. If no checkpoint data is available, the server will shut down.