Title: Warning: require_once() [function.require-once]:
Last modified: August 21, 2016

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# Warning: require_once() [function.require-once]:

 *  [Richard Slade](https://wordpress.org/support/users/raslade/)
 * (@raslade)
 * [12 years, 5 months ago](https://wordpress.org/support/topic/warning-require_once-functionrequire-once/)
 * I’ve installed WordPress as a sub domain on an existing site (www.mainsite.co.
   uk/mywordpressinstall) but when I go to preview the site i’m getting a very odd
   error:
 * Warning: require_once() [function.require-once]: Filename cannot be empty in /
   web1/user33402/website/index.php on line 526
 * Fatal error: require_once() [function.require]: Failed opening required ” (include_path
   =’.:’) in /web1/user33402/website/index.php on line 526
 * Unfortunately I didn’t setup the rest of the site so not entirely sure how it’s
   configured. Any clues how to fix would be great, thanks

Viewing 6 replies - 1 through 6 (of 6 total)

 *  Moderator [t-p](https://wordpress.org/support/users/t-p/)
 * (@t-p)
 * [12 years, 5 months ago](https://wordpress.org/support/topic/warning-require_once-functionrequire-once/#post-4399471)
 * have you discussed with your webhost?
 *  [IncrediPress](https://wordpress.org/support/users/incredipress/)
 * (@incredipress)
 * [12 years, 5 months ago](https://wordpress.org/support/topic/warning-require_once-functionrequire-once/#post-4399477)
 * Who is it hosted with?
 *  Thread Starter [Richard Slade](https://wordpress.org/support/users/raslade/)
 * (@raslade)
 * [12 years, 5 months ago](https://wordpress.org/support/topic/warning-require_once-functionrequire-once/#post-4399494)
 * No not yet. easily.co.uk
 *  [esmi](https://wordpress.org/support/users/esmi/)
 * (@esmi)
 * [12 years, 5 months ago](https://wordpress.org/support/topic/warning-require_once-functionrequire-once/#post-4399505)
 * Try re-uploading all files & folders – **except** the root wp-config.php file–
   from a **fresh** download of WordPress. Make sure that you delete the old copies
   of files & folder before uploading the new ones.
 *  Thread Starter [Richard Slade](https://wordpress.org/support/users/raslade/)
 * (@raslade)
 * [12 years, 5 months ago](https://wordpress.org/support/topic/warning-require_once-functionrequire-once/#post-4399521)
 * No need it’s a clean install and admin works fine. The rest of the site is running
   magento. On the error page this has been added to the address. ?section=site
 *  Thread Starter [Richard Slade](https://wordpress.org/support/users/raslade/)
 * (@raslade)
 * [12 years, 5 months ago](https://wordpress.org/support/topic/warning-require_once-functionrequire-once/#post-4399538)
 * Damn it. It was just the permalinks not holding.

Viewing 6 replies - 1 through 6 (of 6 total)

The topic ‘Warning: require_once() [function.require-once]:’ is closed to new replies.

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 6 replies
 * 4 participants
 * Last reply from: [Richard Slade](https://wordpress.org/support/users/raslade/)
 * Last activity: [12 years, 5 months ago](https://wordpress.org/support/topic/warning-require_once-functionrequire-once/#post-4399538)
 * Status: not resolved

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