Hi - we have had an install of OSticket for several years, and just this week we are getting DB Error 1054 errors every six minutes while one particular user is logged into the system. The rest of the time we don't see them, and we are not sure what is causing this. This user doesn't appear to be doing anything abnormal. We have OSticket version 1.14.1, running on an Ubuntu 16.04 server with PHP 7.0.33. Here is the email of the error that we are getting:

[SELECT COUNT(DISTINCT CASE WHEN A2.state = 'open' AND B4.choices IS NOT NULL AND A2.state = 'open' AND B4.choices IS NOT NULL AND A1.isoverdue = '1' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q16, COUNT(DISTINCT CASE WHEN A1.ticket_id = Z1.ticket_id THEN A1.ticket_id END) AS q17, COUNT(DISTINCT CASE WHEN A2.state = 'open' AND B4.choices IS NOT NULL AND A3.object_type = 'T' THEN A1.ticket_id END) AS q1, COUNT(DISTINCT CASE WHEN (A1.team_id IN (2) OR A1.staff_id IN (66)) AND A2.state = 'open' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q5, COUNT(DISTINCT CASE WHEN (A1.team_id IN (2) OR A1.staff_id IN (66)) AND A2.state = 'open' AND (A1.team_id IN (2) OR A1.staff_id IN (66)) AND A2.state = 'open' AND A1.staff_id IN (66) AND A3.object_type = 'T' THEN A1.ticket_id END) AS q6, COUNT(DISTINCT CASE WHEN (A1.team_id IN (2) OR A1.staff_id IN (66)) AND A2.state = 'open' AND (A1.team_id IN (2) OR A1.staff_id IN (66)) AND A2.state = 'open' AND NOT A1.staff_id IN (66) AND A3.object_type = 'T' THEN A1.ticket_id END) AS q7, COUNT(DISTINCT CASE WHEN A2.state = 'closed' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q8, COUNT(DISTINCT CASE WHEN A2.state = 'closed' AND A2.state = 'closed' AND A1.closed BETWEEN '2021-01-12 00:00:00' AND '2021-01-12 23:59:59' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q9, COUNT(DISTINCT CASE WHEN A2.state = 'closed' AND A2.state = 'closed' AND A1.closed BETWEEN '2021-01-11 00:00:00' AND '2021-01-11 23:59:59' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q10, COUNT(DISTINCT CASE WHEN A2.state = 'closed' AND A2.state = 'closed' AND A1.closed BETWEEN '2021-01-11 00:00:00' AND '2021-01-17 23:59:59' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q11, COUNT(DISTINCT CASE WHEN A2.state = 'closed' AND A2.state = 'closed' AND A1.closed BETWEEN '2021-01-01 00:00:00' AND '2021-01-31 23:59:59' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q12, COUNT(DISTINCT CASE WHEN A2.state = 'closed' AND A2.state = 'closed' AND A1.closed BETWEEN '2021-01-01 00:00:00' AND '2021-03-31 23:59:59' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q13, COUNT(DISTINCT CASE WHEN A2.state = 'closed' AND A2.state = 'closed' AND A1.closed BETWEEN '2021-01-01 00:00:00' AND '2021-12-31 23:59:59' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q14, COUNT(DISTINCT CASE WHEN A2.state = 'open' AND B4.choices IS NOT NULL AND A2.state = 'open' AND B4.choices IS NOT NULL AND A1.isanswered = '1' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q3, COUNT(DISTINCT CASE WHEN A2.state = 'open' AND B4.choices IS NOT NULL AND A2.state = 'open' AND B4.choices IS NOT NULL AND A1.isanswered = '0' AND A3.object_type = 'T' THEN A1.ticket_id END) AS q2 FROM ost_ticket A1 JOIN ost_ticket_status A2 ON (A1.status_id = A2.id) LEFT JOIN ost_thread A3 ON (A3.object_type = 'T' AND A1.ticket_id = A3.object_id) LEFT JOIN ost_thread_referral A4 ON (A3.id = A4.thread_id) LEFT JOIN ost_staff A5 ON (A4.object_type = 'S' AND A4.object_id = A5.staff_id) LEFT JOIN ost_thread A6 ON (A1.ticket_id = A6.object_id AND A6.object_type = 'C') LEFT JOIN ost_thread_referral A7 ON (A6.id = A7.thread_id) LEFT JOIN ost_staff A8 ON (A7.object_type = 'S' AND A7.object_id = A8.staff_id) LEFT JOIN ost_team B0 ON (A4.object_type = 'E' AND A4.object_id = B0.team_id) LEFT JOIN ost_team B1 ON (A7.object_type = 'E' AND A7.object_id = B1.team_id) LEFT JOIN ost_department B2 ON (A4.object_type = 'D' AND A4.object_id = B2.id) LEFT JOIN ost_department B3 ON (A7.object_type = 'D' AND A7.object_id = B3.id) LEFT JOIN ost_ticket__cdata B4 ON (A1.ticket_id = B4.ticket_id) WHERE ((A2.state = 'open' AND (A1.staff_id = 66 OR A5.staff_id = 66 OR A6.object_type = 'C' AND A8.staff_id = 66 OR A1.team_id IN (2) OR B0.team_id IN (2) OR A6.object_type = 'C' AND B1.team_id IN (2))) OR (A2.state IN ('open', 'closed') AND (A1.dept_id IN (1) OR B2.id IN (1))) OR A6.object_type = 'C' AND B3.id IN (1))]

Unknown column 'Z1.ticket_id' in 'field list' 
---- Backtrace ---- 
#0 (root)/include/mysqli.php(200): osTicket->logDBError('DB Error #1054', '[SELECT COUNT(D...') 
#1 (root)/include/class.orm.php(3459): db_query('SELECT COUNT(DI...', true, true) 
#2 (root)/include/class.orm.php(3506): MySqlExecutor->execute() 
#3 (root)/include/class.orm.php(2093): MySqlExecutor->getArray() 
#4 (root)/include/class.orm.php(2043): HashArrayIterator->{closure}() 
#5 (root)/include/class.orm.php(2022): CallbackSimpleIterator->next() 
#6 (root)/include/class.orm.php(2031): CallbackSimpleIterator->rewind() 
#7 (root)/include/class.orm.php(1703): CallbackSimpleIterator->valid() 
#8 (root)/include/class.orm.php(1713): CachedResultSet->fillTo(9223372036854775807) 
#9 (root)/include/class.orm.php(1336): CachedResultSet->asArray() 
#10 (root)/include/class.orm.php(1359): QuerySet->all() 
#11 (root)/include/class.search.php(973): QuerySet->one() 
#12 (root)/scp/autocron.php(43): SavedQueue::counts(Object(StaffSession), false) 
#13 {main}

Any ideas on what is causing this?

Thanks,

Rett Walters