Steps to reproduce:

1. Import template_module_icmp_ping.yaml downloaded from git.zabbix.com templates for 6.0.
2. Spinning icon forever
3. In apache2/errors.log has: 

    PHP Fatal error:  Uncaught Error: Call to a member function getTokensOfTypes() on null in /usr/share/zabbix/include/classes/api/services/CTriggerGeneral.php:1738\nStack trace:\n#0 /usr/share/zabbix/include/classes/api/services/CTriggerGeneral.php(1441): CTriggerGeneral->implode_expressions()\n#1 /usr/share/zabbix/include/classes/api/services/CTriggerGeneral.php(529): CTriggerGeneral->createReal()\n#2 /usr/share/zabbix/include/classes/api/services/CTriggerGeneral.php(537): CTriggerGeneral->inherit()\n#3 /usr/share/zabbix/include/classes/api/services/CTriggerGeneral.php(537): CTriggerGeneral->inherit()\n#4 /usr/share/zabbix/include/classes/api/services/CTrigger.php(553): CTriggerGeneral->inherit()\n#5 /usr/share/zabbix/include/classes/import/CConfigurationImport.php(1729): CTrigger->update()\n#6 /usr/share/zabbix/include/classes/import/CConfigurationImport.php(152): CConfigurationImport->processTriggers()\n#7 /usr/share/zabbix/include/classes/api/services/CConfiguration.php(248): CConfigurationImport->import()\n#8 /usr/share/zabbix/includ in /usr/share/zabbix/include/classes/api/services/CTriggerGeneral.php on line 1738

The install was upgraded from Zabbix 5.0.x to 6.0.5 recently. I have seen the same error trying to import other templates as well.