Don't have Telegram yet? Try it now!
https://blog.devoworx.net/2014/08/02/in-remote-mode-the-report-viewer-control-requires-session-state-be-enabled-or-report-server-connection-information-specified-in-the-config-file/
In remote mode, the Report Viewer control requires session state be enabled or Report Server connection information specified in the config file