Am running wordpress multisite (sub directory) with the following plugins:
All was good, and running smoothly, until we attempted to 'embed' google maps on one of the pages, in a text widget.
Well. By embedding the code in the widget (instead of shortcodes or using a plugin), the map came up, and there may even have been a happy dance going on. Went to clear out the cached pages using the super-cache admin (so everyone else could see our map); it ran for a minute or so, then at the top of the page we saw the contents of what looks like the config php for super-cache, then the following message:
Warning: Cannot modify header information - headers already sent by (output started at /<pathname>/wp-content/wp-cache-config.php:8) in /<pathname>/wp-includes/pluggable.php on line 890.
Hmm. ok. So, we attempt to access one of the sites, and get the above warning message. Then, attempted to get into wp-admin; same message. So, I went to the server, renamed the directory wp-super-cache to wp-super-cache-backup (in effect, deleting the plugin), and was able to get back into wp-admin. Went back to the widget, removed the google maps embedded code, saved the changes, and was then able to get to the site(s). Restored the wp-super-cache to it's original name, went back to the site, and received the same message as above.
So, obviously, one or more of my super-cache files is jacked. The only things I saw on the system with today's date and time accessed were the cache directory, and the wp-cache-config.php. I can easily (I believe) just remove the directory, un-install the plugin, re-install the plugin, re-activate it, and move on with my life.
However. Now when I go into wp-admin, and pull up the plugins page, all of the above are listed, but only 1 shows active (WordPress Importer).
Wait, it gets better...what's more strange, is, that wp-super-cache is still listed (even tho it doesn't exist).
AND, the other plugins? All still work. Even on pages where I have no physical cached file under the cache directory.
In my database, in the wp_sitemeta, meta_key menu_items, I have the following value:
and in my wp_options table, option_name active_plugins, I have:
So, my plan of action: Restore the database (of course, I have a backup), remove all directories/files associated with wp-super-cache, re-install the plug-in, and find another way to display google maps.
Would really like a heads up on what possibly went wrong, so I don't do it again. And, a warm fuzzy that my plan of action above is the way to go.