Recoverable fatal error: Argument 1 must be an instance of stdClass

The following error happened:

Recoverable fatal error: Argument 1 passed to ext_search_page_get_widgets_registry() must be an instance of stdClass, instance of Entity given, called in ..../sites/all/modules/ext_search_page/ext_search_page.admin.inc on line 52 and defined in ext_search_page_get_widgets_registry() (line 190 of ..../sites/all/modules/ext_search_page/ext_search_page.module).