RAD PDF exceptions will only be displayed in your browser if your ASP.NET code or one of the RAD PDF Web Controls is at fault.
For more error / warning information regarding RAD PDF, you should check the Windows Event Log.
In most versions of Windows, event logs can be viewed using the Event Viewer found in the Administrative Tools folder of your Windows Control Panel.
For more information about troubleshooting RAD PDF, please see:
https://www.radpdf.com/RadPdfDocumentation/?topic=html/75619e37-2a95-4803-b3e7-69fbe53d3cae.htm