It seems as though

It seems as though the WHMCS Integration plugin is having a few issues/errors.
Below are two errors that showed up recently... can you help?

Warning: Cannot modify header information - headers already sent by (output started at /home/gsdllc/public_html/wp-includes/functions.php:3996) in /home/gsdllc/public_html/wp-content/plugins/whmcs-wordpress-integration/includes/class-whmcs-wordpress-integration.php on line 307

Notice: Undefined index: pagename in /home/gsdllc/public_html/wp-content/plugins/whmcs-wordpress-integration/includes/class-whmcs-wordpress-integration.php on line 1041

  • Kasia Swiderska

    Hello gsd,

    The error that you are seeing isn't actuall a problem caused by WHMCS Integration plugin.

    It says that some other plugin is printing an output already, therefore WHMCS is not allowed to modify the headers (in this case, WHMCS needs to include some cookies in the headers).

    You need to find the plugin/code that is printing this output before expected.
    One of the most common causes for this is an empty line at the start of a php file.
    Also, it could happen that -when WP_DEBUG is enabled- some plugin is just printing some debugging information.

    I would suggest you to keep only whmcs integration enabled and then activate other plugins one by one until you find which one is causing the error. You should try also with a default theme in case the problem is caused by your theme.
    If you have some custom code in your site, check if there are empty lines at the beginning or end of php files.

    Let me know how it goes.

    kind regards,

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