Deprecated string

When editing the activity:

String [grade,core] is deprecated. Either you should no longer be using that string, or the string has been incorrectly deprecated, in which case you should report this as a bug. Please refer to ``https://docs.moodle.org/dev/String_deprecation

• line 397 of /lib/classes/string_manager_standard.php: call to debugging()
• line 7414 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()
• line 144 of /mod/randomactivity/view.php: call to get_string()