- Go to Admin > Content Types
- Click button + to create content type group
- Fill fields and save
- Click button + to create content type
- Fill necessary fields, add two fieldtypes
- Click Discard changes
- Go to Content Type Groups list
- Select previously created group and delete it
Content type group is empty but we cannot delete it.
Argument '$contentTypeGroup' is invalid: Content type group has content type instances
Content type group is empty and we can delete it.