Board URL is set to 'http://rice21.com', but you currently seem to be on 'http://www.rice21.com'. A wrong Board URL setting may cause problems with Redirect.

Add to .htaccess:
# Some hosts require RewriteBase to make RewriteRules work.
RewriteBase /

# Google SEO workaround for search.php highlights:
# Make this rule the first rewrite rule in your .htaccess!
RewriteRule ^([^&]*)&(.*)$ http://rice21.com/$1?$2 [L,QSA,R=301]

# Google SEO 404:
ErrorDocument 404 /misc.php?google_seo_error=404

# Google SEO Sitemap:
RewriteRule ^sitemap-([^./]+)\.xml$ misc.php?google_seo_sitemap=$1 [L,QSA,NC]

# Google SEO URL Forums:
RewriteRule ^Forum-([^./]+)$ forumdisplay.php?google_seo_forum=$1 [L,QSA,NC]

# Google SEO URL Threads:
RewriteRule ^Thread-([^./]+)$ showthread.php?google_seo_thread=$1 [L,QSA,NC]

# Google SEO URL Announcements:
RewriteRule ^Announcement-([^./]+)$ announcements.php?google_seo_announcement=$1 [L,QSA,NC]

# Google SEO URL Users:
RewriteRule ^User-([^./]+)$ member.php?action=profile&google_seo_user=$1 [L,QSA,NC]

# Google SEO URL Calendars:
RewriteRule ^Calendar-([^./]+)$ calendar.php?google_seo_calendar=$1 [L,QSA,NC]

# Google SEO URL Events:
RewriteRule ^Event-([^./]+)$ calendar.php?action=event&google_seo_event=$1 [L,QSA,NC]
404, Meta, Redirect, Sitemap and URL are enabled. (Configure)
Click to Revert changes to core files.

(2017-01-20, 02:33 PM).m. Wrote: which url you actually want to use - with www or without www ?

in general, many prefer URLs without www
and URLs with www should be redirected to URLs without www   (see replies here)

board url is set through Site Details page of Configuration section in forum admin panel  

rewrite rules suggested by Goole SEO plugin should be added to .htaccess file at the main folder of your MyBB forum

RewriteCond %{HTTP_HOST} ^rice21.com$ [NC]
RewriteRule ^(.*)$ http://www.rice21.com/$1 [R=301,L]

(2017-01-20, 08:20 PM)gunrose2003 Wrote:

(2017-01-20, 02:33 PM).m. Wrote: which url you actually want to use - with www or without www ?

in general, many prefer URLs without www
and URLs with www should be redirected to URLs without www   (see replies here)

board url is set through Site Details page of Configuration section in forum admin panel  

rewrite rules suggested by Goole SEO plugin should be added to .htaccess file at the main folder of your MyBB forum

Thank you for your reply. I like the URL with www.

Now the google SEO module is success, but also have another problem.

When i add the 301 rewrite to the .htaccess.(as below)

RewriteCond %{HTTP_HOST} ^rice21.com$ [NC]
RewriteRule ^(.*)$ http://www.rice21.com/$1 [R=301,L]

Most of links are unavailable, like login, sub forum, registration etc.
I would like to know whether it has conflict with the "Google SEO" module? how to solve it?
Thank you again.