We have created a new “ie11.browser” file in C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\Browsers and now ASP.NET is working correctly. After creating the file we run “aspnet_regbrowsers -i” and restarted IIS.
We simply copied the capabilities of IE6-9. We do not know if this is accurate, but ASP.NET is now working with Explorer 11 running on Windows 8.1
Our ie11.browser file looks like this:
<browsers>
<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="${version}" />
</capabilities>
</browser>
<!-- Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv:11,0) like Gecko -->
<browser id="IE110" parentID="IE11">
<identification>
<capability name="majorversion" match="11" />
</identification>
<capabilities>
<capability name="ecmascriptversion" value="3.0" />
<capability name="jscriptversion" value="5.6" />
<capability name="javascript" value="true" />
<capability name="javascriptversion" value="1.5" />
<capability name="msdomversion" value="${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>
</browsers>