We have just installed SDL Web 8 on a Windows Server 2012 R2 server with SQL Server 2012 SP2 for the database. We ran into a few issues during the installation (one was around the use of host name headers) and ended up having to start over but eventually got it installed.
However, when viewing the Content Manager Explorer (regardless of browser used) we do not see the interface as it should look based upon screenshots we've seen. Instead the main part of the interface appears to be missing some style sheets (though we don't see any errors in the network inspector or console).
We are not able to do anything that you can normally do in the CME. We're about to dump the databases and start from scratch, but wondered if anyone else has seen this. Seems like something simple is missing, but there are no errors in the logs and I would expect things to function after a fresh install (unless we missed some steps).
Update per comments: We have tried this in IE, Chrome and Firefox (and have configured the browsers per the instructions).
While troubleshooting, we found the following error buried within one of the individual XHR requests for the Welcome_v8.1.0.194.5_.aspx?mode=css resource.
System.Web.HttpUnhandledException (0x80004005): Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.ArgumentException: An item with the same key has already been added. at System.Collections.Generic.Dictionary\`2.Insert(TKey key, TValue value, Boolean add) at Tridion.Web.UI.Core.CssPathCorrector.Process(String fileContents, String filePath) at Tridion.Web.UI.Core.CachedCssFile.PreprocessContents(String contents, Boolean debug) at Tridion.Web.UI.Core.CachedFile.get_Contents() at Tridion.Web.UI.Core.CachedFile.WriteContents(HttpResponse response, CachedResourceType resourceType, List\`1 writtenResources) at Tridion.Web.UI.Core.CachedCssGroup.WriteContents(HttpResponse response, CachedResourceType resourceType, List\`1 writtenResources) at Tridion.Web.UI.Core.CachedCssGroup.WriteContents(HttpResponse response, CachedResourceType resourceType, List\`1 writtenResources) at Tridion.Web.UI.Core.CachedCssGroup.WriteContents(HttpResponse response, CachedResourceType resourceType, List\`1 writtenResources) at Tridion.Web.UI.Core.CachedCssGroup.WriteContents(HttpResponse response, CachedResourceType resourceType, List\`1 writtenResources) at Tridion.Web.UI.Core.CachedCssPageResources.WriteContents(HttpResponse response, CachedResourceType resourceType, List\`1 writtenResources) at Tridion.Web.UI.Core.Common.HttpUtilities.OutputWithHTTPCacheHeaders(ICachedResource resource, CachedResourceType resourceType, Nullable\`1 cacheDuration) at Tridion.Web.UI.Controls.TridionPage.Render(HtmlTextWriter writer) at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
That doesn't show up in the console log and we didn't see it in the Tridion event log - it is contained within the response for this particular request. We found it using the Chrome Developer Tools network inspector.
We observed the same thing for some other resources that have ?mode=css specified.