"An error has occurred. Try this action again" occurs when logging into Microsoft Dynamics CRM

When logging into Microsoft Dynamics CRM, the following error is presented to the user.

An error has occurred. 

Try this action again. If the problem continues, check the Microsoft Dynamics CRM Community for solutions or contact your organization's Microsoft Dynamics CRM Administrator. Finally, you can contact Microsoft Support.

Enabling platform tracing and reviewing the trace logs after reproducing the error, administrators will see the following logged.

Process: w3wp |Organization:00000000-0000-0000-0000-000000000000 |Thread:   19 |Category: Application |User: 00000000-0000-0000-0000-000000000000 |Level: Error |ReqId: 211152db-ecd7-4fb2-b516-1570a12ab3ca |ActivityId: 211152db-ecd7-4fb2-b516-1570a12ab3ca | HttpApplication.RecordError  ilOffset = 0x41
    at HttpApplication.RecordError(Exception error)  ilOffset = 0x41
    at PipelineStepManager.ResumeSteps(Exception error)  ilOffset = 0xEE
    at HttpApplication.BeginProcessRequestNotification(HttpContext context, AsyncCallback cb)  ilOffset = 0x31
    at HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context)  ilOffset = 0xB0
    at PipelineRuntime.ProcessRequestNotificationHelper(IntPtr rootedObjectsPointer, IntPtr nativeRequestContext, IntPtr moduleData, Int32 flags)  ilOffset = 0x131
    at PipelineRuntime.ProcessRequestNotification(IntPtr rootedObjectsPointer, IntPtr nativeRequestContext, IntPtr moduleData, Int32 flags)  ilOffset = 0x0
    at UnsafeIISMethods.MgdIndicateCompletion(IntPtr pHandler, RequestNotificationStatus& notificationStatus)  ilOffset = 0xFFFFFFFF
    at UnsafeIISMethods.MgdIndicateCompletion(IntPtr pHandler, RequestNotificationStatus& notificationStatus)  ilOffset = 0xFFFFFFFF
    at PipelineRuntime.ProcessRequestNotificationHelper(IntPtr rootedObjectsPointer, IntPtr nativeRequestContext, IntPtr moduleData, Int32 flags)  ilOffset = 0x1E7
    at PipelineRuntime.ProcessRequestNotification(IntPtr rootedObjectsPointer, IntPtr nativeRequestContext, IntPtr moduleData, Int32 flags)  ilOffset = 0x0
>Request https://ServerName.domain.com/CrmOrganizationName/default.aspx failed with exception System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.Crm.Application.Utility.Util.GetConfigurableThemeStyleParameters()
   at Microsoft.Crm.Application.Utility.Util.GetConfigurableThemeStyleSheetUrl()
   at Microsoft.Crm.Controls.Header..ctor(Boolean isControlHeader)
   at Microsoft.Crm.Controls.BasicHeader..ctor()
   at Microsoft.Crm.Application.Controls.AppHeader..ctor()
   at ASP.default_aspx.__BuildControlcrmHeader()
   at ASP.default_aspx.__BuildControlTree(default_aspx __ctrl)
   at ASP.default_aspx.FrameworkInitialize()
   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.ExecuteStepImpl(IExecutionStep step)
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

One possible cause for this error is that the OrganizationBase table in the OrgName_MSCRM database is missing theme information from the DefaultThemeData and the HighContrastThemeData columns.

Administrators can confirm this by running the following SQL query.

Select DefaultThemeData, HighContrastThemeData from OrganizationBase

If one or both of the above columns are blank, this is more than likely the cause of the problem.

A similar error may occur if the ThemeBase table is empty.

To resolve the error, SQL administrators must update the OrganizationBase table so that it reflects the default and/or high contrast theme information.

The following query will update the OrganizationBase table with the default out of the box theme data.

Update OrganizationBase set DefaultThemeData = 
'<theme themeId="f499443d-2082-4938-8842-e7ee62de9a23" updateTimeStamp="636054720539124867">
 <globallinkcolor>#1160B7</globallinkcolor>
 <selectedlinkeffect>#B1D6F0</selectedlinkeffect>
 <hoverlinkeffect>#D7EBF9</hoverlinkeffect>
 <navbarbackgroundcolor>#002050</navbarbackgroundcolor>
 <navbarshelfcolor>#DFE2E8</navbarshelfcolor>
 <headercolor>#1160B7</headercolor>
 <controlshade>#F3F1F1</controlshade>
 <controlborder>#CCCCCC</controlborder>
 <processcontrolcolor>#D24726</processcontrolcolor>
 <defaultentitycolor>#001CA5</defaultentitycolor>
 <defaultcustomentitycolor>#006551</defaultcustomentitycolor>
 <backgroundcolor>#FFFFFF</backgroundcolor>
 <logoid/>
 <logotooltip>Microsoft Dynamics CRM</logotooltip>
</theme>'

Update OrganizationBase set HighContrastThemeData =
'<theme themeId="f499443d-2082-4938-8842-e7ee62de9a23" updateTimeStamp="636054720539124867">
 <globallinkcolor>#1160B7</globallinkcolor>
 <selectedlinkeffect>#B1D6F0</selectedlinkeffect>
 <hoverlinkeffect>#D7EBF9</hoverlinkeffect>
 <navbarbackgroundcolor>#002050</navbarbackgroundcolor>
 <navbarshelfcolor>#DFE2E8</navbarshelfcolor>
 <headercolor>#1160B7</headercolor>
 <controlshade>#F3F1F1</controlshade>
 <controlborder>#CCCCCC</controlborder>
 <processcontrolcolor>#D24726</processcontrolcolor>
 <defaultentitycolor>#001CA5</defaultentitycolor>
 <defaultcustomentitycolor>#006551</defaultcustomentitycolor>
 <backgroundcolor>#FFFFFF</backgroundcolor>
 <logoid/>
 <logotooltip>Microsoft Dynamics CRM</logotooltip>
</theme>'

NOTE: The above themeid's in both SQL update statements are not unique to your organization. These are the default ID's for any out of the box Microsoft Dynamics CRM themes.