So search is broken, I can't search for a user while trying to add a ticket.
I get below in the log, I can see where it goes wrong, in includ/class.orm.php (lines 2405, where we start building the SQL string for the search)

Version: v1.15.3.1 (65ca4e6)

DB Error #1054
[SELECT A1.id, A1.name, A6.address FROM ost_user A1 LEFT JOIN ost_user_email A2 ON (A1.id = A2.user_id) LEFT JOIN ost_organization A3 ON (A1.org_id = A3.id) LEFT JOIN ost_user_account A4 ON (A1.id = A4.user_id) LEFT JOIN ost_user__cdata A5 ON (A1.id = A5.user_id) LEFT JOIN ost_user_email A6 ON (A1.default_email_id = A6.id) WHERE (A2.address LIKE '%John%' OR A1.name LIKE '%John%' OR A3.name LIKE '%John%' OR A4.username LIKE '%John%' OR A5.phone LIKE '%John%') LIMIT 25] Unknown column 'A5.phone' in 'where clause'

---- Backtrace ----
#0 (root)/include/mysqli.php(201): osTicket->logDBError()
#1 (root)/include/class.orm.php(3466): db_query()
#2 (root)/include/class.orm.php(3522): MySqlExecutor->execute()
#3 (root)/include/class.orm.php(2070): MySqlExecutor->getRow()
#4 (root)/include/class.orm.php(2043): FlatArrayIterator->{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()
#9 (root)/include/class.orm.php(1729): CachedResultSet->asArray()
#10 (root)/include/ajax.users.php(98): CachedResultSet->getIterator()
#11 (root)/include/class.dispatcher.php(145): UsersAjaxAPI->search()
#12 (root)/include/class.dispatcher.php(38): UrlMatcher->dispatch()
#13 (root)/include/class.dispatcher.php(120): Dispatcher->resolve()
#14 (root)/include/class.dispatcher.php(38): UrlMatcher->dispatch()
#15 (root)/scp/ajax.php(316): Dispatcher->resolve()
#16 {main}