As to the error: "Could not load file or assembly 'Telerik.Windows.Controls.DataVisualization...", would you please ensure the assemblies are not blocked and all the references are with the same version? Then Clean and Rebuild your solution.
As to the error: "Required permissions cannot be acquired.", would you please check the configuration and settings of the portal. This error is definitely not raised by our side.
Check out Telerik Analytics, the service which allows developers to discover app usage patterns, analyze user data, log exceptions, solve problems and profile application performance at run time. Watch the videos
and start improving your app based on facts, not hunches.