In a previous thread, I found a solution for the error, "Notice: Undefined index: action in /wp-content/plugins/wordpress-mu-domain-mapping/domain_mapping.php on line 142" - by using the Development Version.
Under Super Admin -> Settings -> Domain -> New Domains I am unable to add new domains. If I put in Site ID, Domain, check Primary, and then Save, it refreshes the page with no indication that it added the information. If I search the domain I just added, nothing appears.
If I go to Sites -> All Sites I do not see the domain I attempted to add.
Both the _domain_mapping and _domain_mapping_log tables are empty.
After enabling WP_DEBUG to fish around I get the previous stated error at the top of the page, "Notice: Undefined index: action..."
Where should I go from here? I'd love to rid this. Thanks for your time ^_^