An unexpected error occured while processing the request.

I want move my webissues server but when i import database to new server. The regular pass login page but got alert 'An unexpected error occured while processing the request.'. When change user_access to 2 in database, user can login but it's the Administrator.

Web server using Ubuntu 16.04 and php7.0

Unhandled System_Db_Exception:  in /var/www/html/webissues/system/db/mysqli/engine.inc.php on line 287
Stack trace:
#0 /var/www/html/webissues/system/db/mysqli/engine.inc.php(110): System_Db_Mysqli_Engine->handleError(Object(mysqli))
#1 /var/www/html/webissues/system/db/mysqli/engine.inc.php(90): System_Db_Mysqli_Engine->executeStatement('SELECT a.alert_...', Array)
#2 /var/www/html/webissues/system/db/connection.inc.php(256): System_Db_Mysqli_Engine->query('SELECT a.alert_...', Array)
#3 /var/www/html/webissues/system/db/connection.inc.php(289): System_Db_Connection->queryArgs('SELECT a.alert_...', Array)
#4 /var/www/html/webissues/system/db/connection.inc.php(277): System_Db_Connection->queryTableArgs('SELECT a.alert_...', Array)
#5 /var/www/html/webissues/system/api/alertmanager.inc.php(460): System_Db_Connection->queryTable('SELECT a.alert_...', 2, 0, 3)
#6 /var/www/html/webissues/cron/job.php(137): System_Api_AlertManager->getAlertsToEmail(true)
#7 /var/www/html/webissues/cron/job.php(72): Cron_Job->sendNotificationEmails()
#8 /var/www/html/webissues/system/core/application.inc.php(210): Cron_Job->execute()
#9 /var/www/html/webissues/system/bootstrap.inc.php(130): System_Core_Application->run()
#10 /var/www/html/webissues/cron/job.php(693): System_Bootstrap::run('Cron_Job')
#11 {main}
An unexpected error occured while executing the command.