SSRS 2016 - Could not load folder contents - and - CATALOG_ERROR_TITLES

Errors:

1) CATALOG_ERROR_TITLES.VIEW_FOLDER_FAILED
2) Could not load folder contents, Something went wrong. Please try again later.

1) CATALOG_ERROR_TITLES.VIEW_FOLDER_FAILED

The first time you start-up the new 2016 SSRS Reports_Preview web site:   http://yourservername\Reports_preview/   you get the following error message:

             CATALOG_ERROR_TITLES.VIEW_FOLDER_FAILED**

             GLOBAL_ERRORS.UNSPECIFIED**

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.

See also:  SSRS 2016: Reports_Preview - 503 Service Unavailable.

2) Could not load folder contents

Something went wrong. Please try again later.

Another issues with CTP 3.3 is the persistent error upon starting the VM.  A simple refresh on the browser seems to resolve this issue.  No service restart necessary.