Reassign the External Content Connectors Service Account user to the global domain
Fix issues with missing user permissions for users on your instance by reassigning the External Content Connectors Service Account user to the global domain.
Symptom
On an instance with domain separation configured, if you assign the External Content Connectors Service Account user to a domain other than the global domain, external content connector user permission crawls can only map source system user and group permissions correctly for instance users assigned to the same domain. Instance users assigned to other domains are unable to search private content indexed by your external content connectors.
Cause
The External Content Connectors application includes an External Content Connectors Service Account user. When you run user permission crawls for your external content connectors, this user account assigns the retrieved source system user and group permissions to users on your instance.
When the External Content Connectors Service Account user is assigned to a domain other than the global domain, it can only map source system user and group permissions to instance users in its own domain. Instance users assigned to any other domain don't get correctly mapped source system user and group permissions and can't search private content retrieved by your external content connectors.
As an example, suppose you have an instance with domain separation configured where you assign the External Content Connectors Service Account user to the PKD/BR 1.0/VK domain. With this configuration, external content connector user permission crawls can only map source system user and group permissions to your instance users who are assigned to the same PKD/BR 1.0/VK domain. Instance users assigned to any other domain don't get source system user and group permissions mapped correctly and can't search private content retrieved by your external content connectors.