общая ошибка при удалении папки install

[гаражный рок]

удалил с корня каталог install и сразу получил в лобешник ошибку, которая под спойлером

Спойлер

SQL ERROR [ mysqli ]

Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'exex.s.session_viewonline' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by [1055]

SQL

SELECT s.session_user_id AS user_id, s.session_viewonline, u.username, u.user_type, u.user_colour FROM phpbb_sessions s LEFT JOIN phpbb_users u ON s.session_user_id = u.user_id WHERE s.session_time >= 1601390190 AND u.user_type <> 2 AND s.session_user_id <> 1 GROUP BY s.session_user_id ORDER BY u.username_clean

BACKTRACE

FILE: (not given by php)
LINE: (not given by php)
CALL: msg_handler()

FILE: [ROOT]/phpbb/db/driver/driver.php
LINE: 855
CALL: trigger_error()

FILE: [ROOT]/phpbb/db/driver/mysqli.php
LINE: 193
CALL: phpbb\db\driver\driver->sql_error()

FILE: [ROOT]/phpbb/db/driver/factory.php
LINE: 329
CALL: phpbb\db\driver\mysqli->sql_query()

FILE: [ROOT]/includes/functions.php
LINE: 4246
CALL: phpbb\db\driver\factory->sql_query()

FILE: [ROOT]/includes/functions.php
LINE: 4994
CALL: obtain_users_online()

FILE: [ROOT]/index.php
LINE: 263
CALL: page_header()

[Sumanai]

sql_mode=only_full_group_by

В принципе достаточно погуглить вот это.