We had a report viewer set up that broke when we migrated from versiion 18.something to the current version because the report viewer would not accept an xmlReportSource.
This is very inconvenient to say the least.
There is some hint in the documentation that you can still do a simple local rendering but all of the viewers seem to only work with the REST service.
I've set up the HTML5 viewer but I had another ReportsController within my project so i had to rename it to keep it from being clobbered by the install of the Rest service.
Once installed I found at runtime that the Reports route was being confused with an entirely separate WebServices project. The only workaround that I found was to rename the controller to TelerikRestReportsController. The call to the viewer is functioning now and you can see in the first attached file that I am getting a response. Unfortunately I am now seeing the following:
Any suggestions would be greatly appreciated.
Using the example Html5ReportViewer1.html i am getting "Telerik Viewer is not defined"
I've tried everything here ReportViewer is undefined JavaScript error is fired when previewing report. | Telerik Reporting
with no luck. My app will not start at all if i switch to a classic app pool
If there were a viewer that i could simply hand the TRDX file to like I used to that would be much simpler and more reliable.
The HTML5-based Report Viewers require the use of a service in order to work display reports so we will need to fix this issue in any case.
If it is saying that the viewer is undefined, then either its JS resource is not loaded on the page with the viewer or jQuery is not being loaded.
My recommendation is to go through the HTML5 WebForms Manual Setup article to ensure that you have implemented everything correctly and that all references are there.
If after that you still get the undefined error message, please see the Getting telerik_reportViewer is not a function console error KB article for more possible reasons.
If you would need further assistance, please try to send attach a runnable project that reproduces the problem so that I may debug it locally.