Server-Side Issues

• Nov 05, 2020

The links below describe how to solve common server-side issues:

The target “X” for the callback could not be found or did not implement ICallbackEventHandler

The controller for ASPxUploadProgressHandlerPage.ashx was not found or does not implement IController

Internal Error. Unable to find the X resource in the Y

Response.Redirect cannot be called in a Page callback

Why you cannot download files on callbacks

A primary key field specified using the KeyFieldName property is not found

The “Key expression is undefined” error occurs when you use LinqServerModeDataSource / EntityServerModeDataSource

Data binding methods such as Eval(), XPath(), and Bind() can only be used for a databound control

Could not find control ‘X’ in ControlParameter ‘Y’

“The X has no access to path Y” or “Access to the path X is denied” (Image and File Controls)

MVC Specifics

Why redirect to another page or View does not work on AJAX requests

Data binding directly to a store query (DbSet, DbQuery, DbSqlQuery, DbRawSqlQuery) is not supported

An alert message with the HTML/JavaScript/CSS content appears when you use callback-aware extensions

An extension with ‘X’ name is already rendered

‘System.Web.WebPages.Html.HtmlHelper’ does not contain a definition for ‘DevExpress’