2) Could not load folder contents, Something went wrong. Please try again later.
1) CATALOG_ERROR_TITLES.VIEW_FOLDER_FAILEDThe first time you start-up the new 2016 SSRS Reports_Preview web site: http://yourservername\Reports_preview/ you get the following error message:
|SSRS 2016 - CATALOG_ERROR_TITLES.VIEW_FOLDER_FAILED|
You click on BUTTONS.OK**, which displays this web page - clearly not what you are expecting.
Restarting the new SSRS Web App (see below) in Services seems to correct the problem.
(update: with Release Candidate 1, SSRS returns to a single service).
SQL Server Reporting Services
SQL Server Reporting Services Web App
After restarting the service, the new web site was operational. The new replacement SSRS service is still under development, so minor issues like this can be expected.