MySQL error, Page 500 error

Hello, im getting this error and on the visitor it shows error 500:
[20-Nov-2019 20:24:09 UTC] PHP Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away in /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php:98
Stack trace:
#0 /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php(98): PDO->query(‘SELECT t0.name …’)
#1 /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(736): MailPoetVendor\Doctrine\DBAL\Driver\PDOConnection->query(‘SELECT t0.name …’)
#2 /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/orm/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php(699): MailPoetVendor\Doctrine\DBAL\Connection->executeQuery(‘SELECT t0.name …’, Array, Array)
#3 /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/orm/lib/Doctrine/ORM/EntityRepository.php(167): MailPoetVendor\Doctrine\ORM\Persisters\En in /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/dbal/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php on line 108
[20-Nov-2019 21:23:21 UTC] PHP Warning: Error while sending QUERY packet. PID=61363 in /home/cactuses/public_html/wp-includes/wp-db.php on line 2030
[20-Nov-2019 21:23:22 UTC] PHP Warning: Error while sending QUERY packet. PID=61365 in /home/cactuses/public_html/wp-includes/wp-db.php on line 2030
[20-Nov-2019 21:23:26 UTC] PHP Warning: Error while sending QUERY packet. PID=61122 in /home/cactuses/public_html/wp-includes/wp-db.php on line 2030
[20-Nov-2019 21:26:48 UTC] PHP Warning: Error while sending QUERY packet. PID=61413 in /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php on line 101
[20-Nov-2019 21:26:48 UTC] PHP Warning: Error while sending QUERY packet. PID=62906 in /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php on line 101
[20-Nov-2019 21:26:48 UTC] PHP Warning: Error while sending QUERY packet. PID=62929 in /home/cactuses/public_html/wp-content/plugins/mailpoet/vendor-prefixed/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php on line 101
[20-Nov-2019 21:27:06 UTC] PHP Warning: Error while sending QUERY packet. PID=61122 in /home/cactuses/public_html/wp-includes/wp-db.php on line 2030

What i should do?

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