This site has gone down suddenly
No files have been changed it just happened over night, when he went to login this morning he get this message.
Is there generally a main reason for this type of error or is it more complicated than that?
I have uploaded a fresh copy of the core WP files but it still shows.
Where would one start troubleshooting this?
Dan | gteh answers:
Does this specific file exist in the location specified?
Also, check your theme files specifically. header.php and index.php and see if any code has been added.
I can probably fix it with FTP and wordpress admin details.
Kailey Lampert answers:
First, disable all plugins. You can do this easily via FTP by renaming the plugins folder (wp-content/plugins/ to wp-content/-plugins/ for example).
If that doesn't work, then can try switching to the default theme.
Can you access server via ftp and db? You can use db codes to deactivate all plugins. The code at the bottom of this does the trick http://perishablepress.com/quickly-disable-or-enable-all-wordpress-plugins-via-the-database/ (backup before doing so!)
Also, reverting to the core 2012 theme may also help. To revert to default theme you can go to the themes folder and simply rename the directory of your current theme.
So if you are using the 'agency' theme
change wp-content/themes/agency to wp-content/themes/agencyX
This will cause wp to not find it and revert, which may allow you into your admin area
Does your server have error logs? That can help you find the exact source of the problem down to the line of code.
Brad Dalton answers:
Download the latest version of WordPress and upload the wp-includes and wp-admin folders overwriting the existing folders on your server.
If you have hacked the core wp files then you better download a copy of these folders before you overwrite them.
I would then install a plugin like Wordfence and change your password to at least 10 digits long using an online password generator.
Take a database backup or backup of your content on a regular basis along with a backup of your files and store it away from your server.
Happy to do this for you also if you want.
Leslie Bogaerts answers:
Go to your ftp program (or file manager in your cpanel) and access the wp-content file. There you disable all the plugins by changing the "plugins" folder to another name, "xplugins" for example. If that fixes the problem, you go to your wp-admin and go to the installed plugins page, that's to make sure that they are deactivated when you change the name of the plugins folder again. Go back to your ftp program or file manager in cpanel and change the name again, then in your wp-admin reactivate each plugin one by one until you find the one that is causing the issue. Remove that plugin and reinstall it. If that doesn't work, you'll have to contact the plugin creator to help you fix the issue.
If deactivating the plugins doesn't work, you'll have to deactivate your theme. Hopefully you still have a default WordPress theme in there (twenty ten, twenty eleven or twenty twelve), if so, changing the name of the active theme folder will revert your theme back to a default theme. If that causes the issue, you'll have to remove the theme and reinstall it to see if that fixes the issue, if not, contact the theme creator to see if they have a fix for you.
Duncan O'Neill answers:
If you still have access to ftp, then adding debugging code will show you what errors are causing this;
add the following four lines, to replace this one line;
The errors should now show in /wp-content/debug.log . Hope this helps.
[ edit ] OK, on looking at the site, it seems that as someone else has suggested /wp-includes/feed.php is missing. That suggests an upgrade has gone wrong. Get rid of /wp-admin/ and /wp-includes/ and replace them with those folders from the [[LINK href="http://codex.wordpress.org/WordPress_Versions"]]Wordpress version[[/LINK]] you were using.