Steps to reproduce:

1. Install zabbix agent or zabbix agent 2 on windows
2. Configure userparameter to be used as metadata item and hostname item, ex: UserParameter=zabbix.hostname,hostname & UserParameter=zabbix.metadata,templates=windows-active
3. Set the item defined for HostNameItem & HostMetadatItem
4. Stop/start the service => it will not accept the userparameter (if you set the same item directly as a command, it will be processed correctly)

Result:

Service cannot start due to fail to process the hostname item.

Expected:

As in Linux agent, userparameter should be accepted as argument for those parameters.