ORA-32010 for reset db_file_multiblock_read_count

hello,

      My database is in version 11.2.0.3 and i would like reset my parameter "db_file_multiblock_read_count", now is set up to 128.

then i did :

>>>>>show parameter db_file_multiblock_read_count;

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

db_file_multiblock_read_count        integer     128

>>>>> alter system reset db_file_multiblock_read_count scope=MEMORY

*

ERROR at line 1:

ORA-32029: resetting with SCOPE=MEMORY or SCOPE=BOTH is currently not supported

SQL> alter system reset db_file_multiblock_read_count;

alter system reset db_file_multiblock_read_count

*

ERROR at line 1:

ORA-32010: cannot find entry to delete in SPFILE

SQL> alter system reset db_file_multiblock_read_count scope=BOTH;