SQL error background job #2688

2016-12-15T09:45:06+0100
2016-12-15T09:15:07+0100
2016-12-15T08:45:02+0100
2016-12-15T08:15:01+0100
2016-12-15T07:45:02+0100

Error while running background job (Doctrine\DBAL\Exception\SyntaxErrorException): An exception occurred while executing 'DELETE FROM `oc_activity_mq` WHERE `amq_timestamp` <= ? AND `amq_affecteduser` IN ()' with params [1481784301]: SQLSTATE[42000]: Syntax error or access violation:   1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1
OCA\Activity\BackgroundJob\EmailNotification ):
/media/f147882d-b410-4463-873b-e1b81659918a/www/cloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/DBALException.php - line 128: Doctrine\DBAL\Driver\AbstractMySQLDriver->convertException('An exception oc...', Object(Doctrine\DBAL\Driver\PDOException))
/media/f147882d-b410-4463-873b-e1b81659918a/www/cloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Statement.php - line 178: Doctrine\DBAL\DBALException driverExceptionDuringQuery(Object(Doctrine\DBAL\Driver\PDOMySql\Driver), Object(Doctrine\DBAL\Driver\PDOException), 'DELETE FROM `oc...', Array)
/media/f147882d-b410-4463-873b-e1b81659918a/www/cloud/apps/activity/lib/MailQueueHandler.php - line 334: Doctrine\DBAL\Statement->execute(Array)
/media/f147882d-b410-4463-873b-e1b81659918a/www/cloud/apps/activity/lib/BackgroundJob/EmailNotification.php - line 131: OCA\Activity\MailQueueHandler->deleteSentItems(Array, 1481784301)
/media/f147882d-b410-4463-873b-e1b81659918a/www/cloud/apps/activity/lib/BackgroundJob/EmailNotification.php - line 81: OCA\Activity\BackgroundJob\EmailNotification->runStep(500, 1481784301)
/media/f147882d-b410-4463-873b-e1b81659918a/www/cloud/lib/private/BackgroundJob/Job.php - line 53: OCA\Activity\BackgroundJob\EmailNotification->run(NULL)
/media/f147882d-b410-4463-873b-e1b81659918a/www/cloud/lib/private/BackgroundJob/TimedJob.php - line 54: OC\BackgroundJob\Job->execute(Object(OC\BackgroundJob\JobList), Object(OC\Log))
/media/f147882d-b410-4463-873b-e1b81659918a/www/cloud/cron.php - line 121: OC\BackgroundJob\TimedJob->execute(Object(OC\BackgroundJob\JobList), Object(OC\Log))
{main}