https://www.zabbix.com/documentation/current/manual/introduction/whatsnew500
says:

SNMP version and credentials in previous versions were set at an item level. In the new version, all of these can be set at a host interface level

According to https://www.zabbix.com/forum/in-russian/401525-zabbix-5-0-%D0%BD%D0%B5-%D1%80%D0%B0%D0%B1%D0%BE%D1%82%D0%B0%D0%B5%D1%82-%D0%BF%D1%80%D0%BE%D1%82%D0%BE%D0%BA%D0%BE%D0%BB-snmp-v1

this may lead to problem if hosts have different snmp versions on items and there is no documented procedure how to find such items ans set host snmp values accordingly before upgrade from 4.4 to 5.0.

This prevents me from upgrade to 5.0.

Thank you!