The 8.0 on-site version is available for the support team, but please, contact our support, so we can provide more details regarding your specific needs.
I've created a new application on Creatio 8.0 with a simple object that only has a lookup to a contact object. When I save a new record "Candidat", nothing happens even though it seems to be correctly configured.
We have received the duplicate request from you sent to support@creatio.com, based on latest information from a request , the issue has been already resolved from your side "by simply adding and removing the "UsrName" field in the "Candidats" form".
Please let us know if the issue persists.
Best regards,
Anastasiia