. Net4.0 's website appears in IE10, IE11 "__dopostback undefined" solution.

Method One, the browser is set to compatibility mode.

Method Two, install the server version. NET40 's patch. http://download.csdn.net/detail/5653325/6642051

Method Three, click on the VS Tool menu--"library package Manager--" Package Manager console ( if there is no "library Package Manager" menu, click on the "Extension Manager", install a "NuGet Package Manager", then there will be. ), a console connected to the PowerShell will appear below the click, and when the console has finished loading, enter

Install-package App_browsersupdate Enter

After the installation is complete, a app_browsersupdate directory appears under the Web site root directory. Then access will not appear "__doPostBack undefined" error.

The above method three can not solve the IE11 under the NET4.0 "__dopostback undefined" approach.

The workaround for IE11 is (choose one of the following method two):

First, the server installation. net4.0 patches (: http://download.csdn.net/detail/5653325/6642051)

Second, in the above method three generated App_browsers\ie.browser add the following text, at the top of the <browsers> below:

<browser id="IE11"Parentid="Mozilla"> <identification> <useragent match="trident\/7.0; rv: (? ') Version ' (? ') Major ' \d+) (\. (? ') Minor ' \d+)?) (?‘ Letters ' \w*)) (? ') Extra ' [^]]*)"/> <useragent nonmatch="Iemobile"/> </identification> <capture> <useragent match="trident/(? ') Layoutversion ' \d+)"/> </capture> <capabilities> <capability name="Browser"Value="IE"/> <capability name="Layoutengine"Value="Trident"/> <capability name="layoutengineversion"Value="${layoutversion}"/> <capability name="Extra"Value="${extra}"/> <capability name="IsColor"Value="true"/> <capability name="Letters"Value="${letters}"/> <capability name="MajorVersion"Value="${major}"/> <capability name="MinorVersion"Value="${minor}"/> <capability name="screenbitdepth"Value="8"/> <capability name="type"Value="Ie${major}"/> <capability name="version"Value="${version}"/> </capabilities> </browser> <!--mozilla/5.0(Windows NT6.3; trident/7.0; Rv: One,0) Like Gecko--<browser id="IE110"Parentid="IE11"> <identification> <capability name="MajorVersion"Match=" One"/> </identification> <capabilities> <capability name="ecmascriptversion"Value="3.0"/> <capability name="jscriptversion"Value="5.6"/> <capability name="JavaScript"Value="true"/> <capability name="javascriptversion"Value="1.5"/> <capability name="msdomversion"Value="${majorversion}.${minorversion}"/> <capability name="w3cdomversion"Value="1.0"/> <capability name="exchangeomasupported"Value="true"/> <capability name="ActiveXControls"Value="true"/> <capability name="backgroundsounds"Value="true"/> <capability name="Cookies"Value="true"/> <capability name="Frames"Value="true"/> <capability name="javaapplets"Value="true"/> <capability name="Supportscallback"Value="true"/> <capability name="Supportsfileupload"Value="true"/> <capability name="Supportsmultilinetextboxdisplay"Value="true"/> <capability name="Supportsmaintainscrollpositiononpostback"Value="true"/> <capability name="Supportsvcard"Value="true"/> <capability name="supportsxmlhttp"Value="true"/> <capability name="Tables"Value="true"/> <capability name="SupportsAccesskeyAttribute"Value="true"/> <capability name="TagWriter"Value="System.Web.UI.HtmlTextWriter"/> <capability name="VBScript"Value="true"/> </capabilities> </browser>