I am getting the following error:

Unable to cast COM object of type 'System.__ComObject' to interface type 'Microsoft.Office.Core.IRibbonUI.'

The OnePlaceMail Outlook add-in encountered an unexpected issue.

Error: Unable to cast COM object of type 'System._ComObject' to interface type 'Microsoft.Office.Core.IRibbonUI'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{000C03A7-0000-0000-C000-000000000046}' failed due to the following error: Library not registered. (Exception from HRESULT: 0x8002801D (TYPEE_LIBNOTREGISTERED)).

Application: mscorlib
Method: IntPtr GetCOMIPFromRCW(System.Object, IntPtr, IntPtr ByRef, Boolean ByRef)
Stack Trace: at System.StubHelpers.StubHelpers.GetCOMIPFromRCW(Object objSrc, IntPtr pCPCMD, IntPtr& ppTarget, Boolean& pfNeedsRelease)
at Microsoft.Office.Core.IRibbonUI.InvalidateControl(String ControlID)
at FileToWSSOutlookAddIn.OPMOutlookRibbon.RebuildMoveAndCopyRecentLocations()
at FileToWSSOutlookAddIn.OPMOutlookRibbon.a(Object A0, EventArgs A1)
at Scinaptic.OnePlaceMail.API.Core.ConfigurationBase.a(Object A0, FileSystemEventArgs A1)
at System.IO.FileSystemWatcher.OnChanged(FileSystemEventArgs e)
at System.IO.FileSystemWatcher.NotifyFileSystemEventArgs(Int32 action, String name)
at System.IO.FileSystemWatcher.CompletionStatusChanged(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* overlappedPointer)
at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP)