Fatal error while opening courses in Snap theme

[amita435]

Fatal error: Declaration of theme_snap\output\core\course_renderer::course_section_cm_completion($course, &$completioninfo, cm_info $mod, $displayoptions = []) must be compatible with core_course_renderer::course_section_cm_completion() in /var/www/moodle_1click/theme/snap/classes/output/core/course_renderer.php on line 29

The error comes while debugging.

Please help. New to Moodle.