Resolved
Overview of the issue
While editing a post or page, if you use the button to insert a gallery on the same page, then the following fatal error is displayed:
- Fatal error: Class ‘WP_Installer_API’ not found in …/sitepress-multilingual-cms/classes/end-user/class-wpml-end-user-loader-factory.php on line 72
Workaround
This issue will be fixed in the future WPML release. For now, you can use the following workaround.
Edit the ../sitepress-multilingual-cms/classes/end-user/class-wpml-end-user-loader-factory.php file and replace the function on line 71:
private function is_site_registered() { return false !== WP_Installer_API::get_site_key( 'wpml' ); }
with the following, updated function code:
private function is_site_registered() { if (class_exists('WP_Installer_API')) { return false !== WP_Installer_API::get_site_key( 'wpml' ); } return false; }
This was bothering me for 3 hours yesterday, this and broken pagination on front-end. Problem was I didn’t get any error at all, no fatal, no warning not even a notice. This workaround fixed it so thank you and please include it in core as soon as possible 🙂