Debugging & Troubleshooting
There are three places to look at, when you encounter error messages during the creation or testing of your report. The application.log, which you can access through the Aministration interface, the session.log, which is shown in the Session Administration or the console of your browser.
Have a look at the application.log whenever there is an "Uncaught Fatal Application Error" or an "Internal server error (500)" in your browser console. The error will be displayed in the log and most of the time easy to comprehend.
The session.log displays error messages, warnings or notices, based on the problems that occured. At least error messages and warnings should be solved, as they are intentionally logged by the system and these messages are referring to false usage of API and much more.
The browser console should be consulted, if there is no error message in the session.log, but the report is not displayed correctly.