The HTML5 Viewer can display reports created by both existing Report Designers. Please check the How it works section in the overview of the HTML5 Viewer and How to: Set ReportSource for Report Viewers.
The HTML5 Viewer can be separated from the Reporting REST service. The viewer sends short messages to get resources which are processed and rendered on the server. It is the Reporting REST service that handles the messages and that generates/delivers the requested resources.
The service comes with default report resolvers which attempt to resolve the viewer's reportSource.Report
string as a TypeReportSource or a UriReportSource. You can use also a custom report resolver and add custom logic for getting a report by the received string description, and then create other type of report source object. For more details check REST Service Report Resolver.
Requested report are processed and rendered on the server. The service will place them in the configured cache storage and it will let you reuse the already rendered reports depending on the service's cache settings
The recommended troubleshooting approach for the HTML5 Viewer is to use Fiddler or other proxy tool to check the requests, their responses and statuses. Information about requests and responses content can be seen in Fiddler - Inspectors - Request/Response - Raw tabs. This will let you check requests to the Reporting REST service and if the URLs are correct (if relative paths are resolved correctly).
Note that relative paths may need adjustment depending on how the application is hosted.
Let us know if you have any further concerns.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items