Cause: Failed to create a new filename record entry in the control file
because the maximum allowed filename records have been allocated
and are in use.
Action: Free up controlfile filename section entries by dropping unwanted
tablespaces/datafiles/redofiles.
Related posts
ORA-00243 Failed to expand control file filename section by %s records
ORA-00243 Failed to expand control file filename section by %s records
Oracle Database Internal Mechanism 