oracle error- ORA-00382: %s not a valid block size, valid range [string..string]

ORA-00382:	%s not a valid block size, valid range [string..string]
Cause:	User specified a value for db_nk_cache_size where n is one of {2, 4, 8, 16, 32}, but nk is not a valid block size for this platform.
Action:	Remove corresponding parameter from the "init.ora" file and restart the instance.