If you faced with the following error when try to open Sharepoint 2013 site:
This operation can be performed only on a computer that is joined to a server farm by users who have permissions in SQL Server to read from the configuration database. To connect this server to the server farm, use the SharePoint Products Configuration Wizard, located on the Start menu in Microsoft SharePoint 2010 Products.
Stack trace:
Microsoft.SharePoint.Utilities.SPUtility.AlternateServerUrlFromHttpRequestUrl(Uri url) +262
Microsoft.SharePoint.Administration.SPAlternateUrl.GetContextUri(HttpContext ctx) +385
Microsoft.SharePoint.SPAppRequestContext.InitCurrent(HttpContext context) +976
Microsoft.SharePoint.SPAppRequestContext.get_Current() +175
Microsoft.SharePoint.SPGlobal.CreateSPRequestAndSetIdentity(SPSite site, String name, Boolean bNotGlobalAdminCode, String strUrl, Boolean bNotAddToContext, Byte[] UserToken, SPAppPrincipalToken appPrincipalToken, String userName, Boolean bIgnoreTokenTimeout, Boolean bAsAnonymous) +400
Microsoft.SharePoint.SPRequestManager.GetContextRequest(SPRequestAuthenticationMode authenticationMode) +120
Microsoft.SharePoint.Administration.SPFarm.get_RequestAny() +370
Microsoft.SharePoint.SPLanguageSettings.GetGlobalInstalledLanguages(Int32 compatibilityLevel) +39
Microsoft.SharePoint.Administration.SPTemplateFileSystemWatcher.RefreshInstalledLocales() +103
Microsoft.SharePoint.Administration.SPTemplateFileSystemWatcher.Initialize() +130
Microsoft.SharePoint.ApplicationRuntime.SPRequestModule.System.Web.IHttpModule.Init(HttpApplication app) +873
System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +582
System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +322
System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +384
System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +397
System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +646
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +159
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +771
Before to run Sharepoint Configuration Wizard go to Windows services and ensure that SQL Server service is running there. Sharepoint shows this error also when SQL server is stopped.