I installed Affiliates plug in.But I can not change

Hi! I installed Affiliates plug in.But I can not change Affiliate Link URL in Settings.
Currently a link is http://onlinelanguage.info. And I want to change it to http://onlinelanguage.info/?page_id=1204.

But after improving link, When I push update settings.(page moved to http://onlinelanguage.info/wp-admin/admin.php?page=affiliatesadminsettings&subpage=&action=updateaffiliateoptions) It showed 403 Error-Forbidden.
Please teach me how to change Affiliate Link URL.