Title: PHP Error with Gravity Forms
Last modified: November 18, 2019

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# PHP Error with Gravity Forms

 *  [shinylab](https://wordpress.org/support/users/shinylab/)
 * (@shinylab)
 * [6 years, 5 months ago](https://wordpress.org/support/topic/php-error-with-gravity-forms/)
 * I’d like to buy Sliced invoices, but I have an issue when activating the Gravity
   Form addon. Gravity forms works great. But when I activate the Sliced Invoice
   Gravity Forms addon… I get this error on all my pages (public and dashboard)
 * “Warning: Declaration of Sliced_Invoices_GF::plugin_row() should be compatible
   with GFAddOn::plugin_row($plugin_name, $plugin_data) in…
 * Warning: Cannot modify header information – headers already sent by (output started
   at /homepages/10/d740132604/htdocs/clickandbuilds/AnnuaireSouffranceetTravail/
   wp-content/plugins/sliced-invoices-gravity-forms/class-sliced-invoices-gf.php:
   754) in …”
 * How can I resolve the issue?
 * Many many Thanks

The topic ‘PHP Error with Gravity Forms’ is closed to new replies.

 * ![](https://ps.w.org/sliced-invoices/assets/icon.svg?rev=1314180)
 * [Sliced Invoices - WordPress Invoice Plugin](https://wordpress.org/plugins/sliced-invoices/)
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 * 0 replies
 * 1 participant
 * Last reply from: [shinylab](https://wordpress.org/support/users/shinylab/)
 * Last activity: [6 years, 5 months ago](https://wordpress.org/support/topic/php-error-with-gravity-forms/)
 * Status: not resolved