ScriptManager::AsyncPostBackErrorMessage Property
Gets or sets the error message that is sent to the client when an unhandled server exception occurs during an asynchronous postback.
Assembly: System.Web.Extensions (in System.Web.Extensions.dll)
The AsyncPostBackError event is raised when there is a page error during asynchronous postbacks. How errors on the server are sent to the client depends on the AllowCustomErrorsRedirect property, the AsyncPostBackErrorMessage property, and the custom errors section of the Web.config file.
The following example shows how to handle the AsyncPostBackError event to set the AsyncPostBackErrorMessage property (which is sent to the client) to the server exception error message.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.