Support » Plugin: BackWPup - WordPress Backup Plugin » Warning: session_start()

  • I’m using BackWPup with success on a number of sites, but this one is on a separate server from most of my sites. In the admin section, the following is displayed at the top of the BackWPup page:

    Warning: session_start() [function.session-start]: open(/home/, O_RDWR) failed: Permission denied (13) in /home/ on line 250
    Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/ in /home/ on line 250
    Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/ in /home/ on line 250


Viewing 6 replies - 1 through 6 (of 6 total)
  • I just had something similar happen when my hosting had to move me from one server to another. My issue was caused by permissions not set correctly on that /tmp directory on my new server.

    Maybe this’ll help someone (I find answers in the forums all the time, but never really get to give back).

    I hope it helps!


    I am facing the same problem. However, the problem is present on some installations but not others on the same server. I had a look at my /tmp directory permissions – but couldn’t see any differences. I did notice that the plugin now uses two temp directories instead of the earlier 1 (in previous versions before the last couple of updates).

    Could you be a little more specific about what you did to fix the permissions?


    Plugin Author Daniel Hüsken



    did you have test Version 3.0.7?

    There i have set the BackWPup temp dir for sessions temp dir if the default issend writeable.


    Yes, I have version 3.0.7.

    As a follow up, on further investigation I found that once I activated the plugin, and visited the Settings -> Information section, the plugin resumed working without a problem and the warning messages disappeared. I was checking if Safe mode was on – as one of the support threads suggested as much – but found that was not the case.

    Not sure why this resolved the problem – but I could replicate it on a couple of sites. Hope this helps you investigate and resolve it.


    Hello again,

    Just my followup info… I don’t believe my issue was specific to this plugin, but is what brought the issue to the surface — unless using that /tmp is a flaw.

    As you see it the original poster’s Warning msgs above, /tmp is at the same level as his /public_html, I had a similar situation. We don’t have access ourselves above our ‘root’ (the /html dir) so I could not check permissions myself, I was at the mercy of the hosting service.

    After 45mins on the phone with the first level support, I was finally able to get them to bump up a level in the service chain and they discovered that permissions were not set properly.

    Hope it helps.

    hello i have the similar problem

    Warning: session_start() [function.session-start]: open(C:\Windows\Temp\\sess_fgstfchr102geqkcmp0jgn2da5, O_RDWR) failed: Invalid argument (22) in D:\Hosting\12111878\html\nihil\wp-includes\plugin.php on line 429

    line code

    // Sort
    if ( !isset( $merged_filters[ $tag ] ) ) {
    $merged_filters[ $tag ] = true;

    reset( $wp_filter[ $tag ] );

    do {
    foreach ( (array) current($wp_filter[$tag]) as $the_ )
    if ( !is_null($the_[‘function’]) )
    call_user_func_array($the_[‘function’], array_slice($args, 0, (int) $the_[‘accepted_args’]));

    } while ( next($wp_filter[$tag]) !== false );


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