1. Create two host groups "G1" and "G2".
2. Create a user group and give it read-write permissions to "G1". Nothing to "G2" (user will not have permissions to this group).
3. Create a regular admin user in that user group.
4. Create a host and place it in "G1".
5. Create a LLD rule in that host and add host prototype. Add "G2" to host prototype.
6. Save everything and go host list.
7a. Export host via frontend.
Observe error in XML file: "[error] System error occurred. Please contact Zabbix administrator." This doesn't give an explanation why, but it does stop user from exporting an invalid XML file.
7b. Export via API (configuration.export)
Observe empty tag "<group/>" which is missing a group name G2 that user has no permissions to. G2 shouldn't be there, that's correct. And "<group_links/>" cannot be empty as well. So re-importing this host will not work, since the validation will fail.