The problem comes from the fact the account used in the application pool identity is not recognized as a trusted account ( account with proper permissions ) in the database. In order to resolve the issue, you can choose NetworkService
as an application pool identity for the application pool used by the application. I have attached a screenshot of the setting.
All the best,
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items