Object.assign is used to query for users, groups, and tenants (see [1], [2], [3]).

But Object.assig is not supported by Internet Explorer.

[1]: https://github.com/camunda/camunda-bpm-webapp/blob/master/ui/admin/client/scripts/pages/users.js#L55-L64
[2]: https://github.com/camunda/camunda-bpm-webapp/blob/master/ui/admin/client/scripts/pages/groups.js#L55-L64
[3]: https://github.com/camunda/camunda-bpm-webapp/blob/master/ui/admin/client/scripts/pages/tenants.js#L55-L64