Fatal error: Call to undefined function wp_get_raw_referer() …../public_html/wp-content/plugins/foogallery/freemius/includes/class-freemius.php on line 7148

Line 7148 has the following text. We have not activated or deactivated any versions.
/**

* Unregister the uninstall hook for the other version of the plugin (with different code type) to avoid

* triggering a fatal error when uninstalling that plugin. For example, after deactivating the “free” version

* of a specific plugin, its uninstall hook should be unregistered after the “premium” version has been

* activated. If we don’t do that, a fatal error will occur when we try to uninstall the “free” version since

* the main file of the “free” version will be loaded first before calling the hooked callback. Since the

* free and premium versions are almost identical (same class or have same functions), a fatal error like

* “Cannot redeclare class MyClass” or “Cannot redeclare my_function()” will occur.

*/