stopped working

Hello, tell me what could be the problem, that Ad Inserter stopped working and gives:

[Thu Mar 19 13:23:33.860042 2020] [lsapi:notice] [pid 3190281] [client 178.125.114.57:42886] [host test7.moytop.by] Backend log: PHP Warning: Illegal string offset ‘global’ in /var/www/a600952/data/www/test7.moytop.by/wp-content/plugins/ad-inserter/ad-inserter.php on line 4866\n, referer: https://test7.moytop.by/wp-admin/
[Thu Mar 19 13:23:33.860082 2020] [lsapi:error] [pid 3190281] [client 178.125.114.57:42886] [host test7.moytop.by] Backend fatal error: PHP Fatal error: Uncaught Error: Cannot use string offset as an array in /var/www/a600952/data/www/test7.moytop.by/wp-content/plugins/ad-inserter/ad-inserter.php:4866\nStack trace:\n#0 /var/www/a600952/data/www/test7.moytop.by/wp-content/plugins/ad-inserter/ad-inserter.php(5884): get_hook_name(1)\n#1 /var/www/a600952/data/www/test7.moytop.by/wp-content/plugins/ad-inserter/ad-inserter.php(9656): ai_load_settings()\n#2 /var/www/a600952/data/www/test7.moytop.by/wp-settings.php(362): include_once(‘/var/www/a60095…’)\n#3 /var/www/a600952/data/www/test7.moytop.by/wp-config.php(97): require_once(‘/var/www/a60095…’)\n#4 /var/www/a600952/data/www/test7.moytop.by/wp-load.php(37): require_once(‘/var/www/a60095…’)\n#5 /var/www/a600952/data/www/test7.moytop.by/wp-admin/admin.php(34): require_once(‘/var/www/a60095…’)\n#6 /var/www/a600952/data/www/test7.moytop.by/wp-admin/plugins.php(10): require_once(‘/var/www/a60095…’)\n#7 {main}\n thrown in /var/www/a600952/data/www/test7.moytop.by/wp-content/plugins/ad-inserter/ad-inserter.php on line 4866\n, referer: https://test7.moytop.by/wp-admin/

At least about what you can pay attention to.
I tried php 5.6-7.3, downloaded and reinstalled the new version.