My Previous PHP version : 7.0.9 and now i have used 7.4.7
does this caused this issue ?
i tried re-uploading SQL file & also files have been re-uploaded / cleared cache from admin
even tried change my DB collation from utf8_general_ci to utf8_bin !!
SQL ERROR [ mysqli ]
Field 'topic_id' doesn't have a default value 
INSERT INTO phpbb_topics (topic_poster, topic_time, topic_last_view_time, forum_id, icon_id, topic_posts_approved, topic_posts_softdeleted, topic_posts_unapproved, topic_visibility, topic_delete_user, topic_title, topic_first_poster_name, topic_first_poster_colour, topic_type, topic_time_limit, topic_attachment, topic_status, topic_desc) VALUES (2, 1593240560, 1593240560, 3, 0, 1, 0, 0, 1, 0, 'fddddfdf d fdfdf', 'manigopal', 'AA0000', 0, 0, 0, 0, 'fdfd bnbn b b')
FILE: (not given by php)
LINE: (not given by php)