RewriteRule: cannot compile regular expression

RewriteRule: cannot compile regular expression

i am getting the follwoing error
RewriteRule: cannot compile regular expression
'^/?(\d+)/?([a-zA-Z0-9-_]*)(\.html|/)?$'\n
My htaccess configuration below:
RewriteRule ^/?mokuji - [S=1] RewriteRule
^/?(\d+)/?([a-zA-Z0-9-]+)/([a-zA-Z0-9-/]+)(.html)?$
index.php?pid=$1&pkey=$2&pkey_ext=$3&%{QUERY_STRING}
Where i am making mistake?
Thank you.