1. Go to Permissions in front page or user permissions(capability overview)
2. receive this error below

Invalid get_string() identifier: 'game:addinstance' or component 'mod_game'. Perhaps you are missing $string['game:addinstance'] = ''; in mod/game/lang/en/game.php?
line 6913 of \lib\moodlelib.php: call to debugging()
line 7605 of \lib\moodlelib.php: call to core_string_manager->get_string()
line 2799 of \lib\accesslib.php: call to get_string()
line 2657 of \lib\accesslib.php: call to get_capability_string()
line 116 of \admin\roles\lib.php: call to get_capability_docs_link()
line 200 of \admin\roles\permissions.php: call to capability_table_base->display()