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".