Fires on the client if any server error occurs during server-side processing of a callback sent by ASPxClientQueryBuilder.
The event handler receives an argument of the ASPxClientCallbackErrorEventHandler type.
The CallbackError event enables you to properly respond to a server error occurring as a result of a callback being processed on the server side. Handle this event to perform specific client-side actions, such as displaying explanatory text or an image related to the error.
Typically, a server error which occurs during server-side processing of a callback, leads to web application hanging, because, in this case, no proper response is generated for a control that initiated the callback. However, AJAX-enabled web controls from the DevExpress product line are able to automatically catch server errors occurring within handlers of their server-side events, and to pass the related error information to the client for further processing through the CallbackError event's argument.
To learn more, see the Handling Callback Exceptions on Client topic.