ORA-01678: parameter db_file_name_convert must be pairs of pattern and replacement strings

SQL> alter system set db_file_name_convert ='' scope=spfile sid='*';

alter system set db_file_name_convert ='' scope=spfile sid='*'

*

ERROR at line 1:

ORA-32017: failure in updating SPFILE

ORA-01678: parameter db_file_name_convert must be pairs of pattern and replacement strings

SQL> alter system reset db_file_name_convert scope=spfile sid='*';

System altered.