PHP7 - PHP Fatal error: Uncaught Exception: Database failure. - when using Grinmark contact synchroniser/SOAP

Hi,
I am using grinmark to synchronize suitecrm contacts to outlook, which has worked reasonably well in the past. I recently updated to 7.4.5 and also updated to php7 and although suitecrm seems to work ok, i have lost synchronisation and get the error shown below in the apache log. There are no entries in the suitecrm.log.

How do i go about troubleshooting this? Is it related to SOAP?

thank you.

[Sun Oct 16 21:20:16.621397 2016] [:error] [pid 29464] [client 192.168.1.41:55474] PHP Fatal error: Uncaught Exception: Database failure. Please refer to suitecrm.log for details. in /var/www/crm/include/utils.php:1623\n

Stack trace:\n

#0 /var/www/crm/include/database/DBManager.php(345): sugar_die(‘Database failur…’)\n

#1 /var/www/crm/include/database/DBManager.php(321): DBManager->registerError(‘Error retrievin…’, ‘Error retrievin…’, true)\n

#2 /var/www/crm/include/database/MysqliManager.php(159): DBManager->checkError(‘Error retrievin…’, true)\

n#3 /var/www/crm/include/database/MysqlManager.php(277): MysqliManager->query(’ SELECT contac…’, true, ‘Error retrievin…’)\n

#4 /var/www/crm/data/SugarBean.php(3520): MysqlManager->limitQuery(’ SELECT contac…’, 0, 2, true, ‘Error retrievin…’)\n

#5 /var/www/crm/data/SugarBean.php(2863): SugarBean->process_list_query(’ SELECT contac…’, 0, 2, 2, ‘(contacts.date_…’)\n

#6 /var/www/crm/soap/SoapSugarUsers.php(360): SugarBean->get_list(’’, ‘(contacts.date_…’, 0, -1, -1, 0, true)\n

#7 /var/www/crm/include/nusoap/nusoap.php(5354): get_entry_list(‘9ndlljvdadmkb2h…’, in /var/www/crm/include/utils.php on line 1623