Impossible to join the group to the tenant

Hello.
I had questions with building a hierarchy using the multitenancy addon. I used the suggested answer and faced new limitations.
Playback error step by step:

  1. I install multitenancy addon.
  2. I prescribe the creation of a group in the code:

@AccessGroup(name = “main_group”)
public class MainGroup extends AnnotatedAccessGroupDefinition {
}

  1. I’m trying to create a new tenant with the above group.

image

When I click “OK” I get an error:

image

CUBA Platform version: 7.2.8
Multitenancy add-on: 2.0.2
Java version: 1.8

Tell me please, what could be wrong?)