Interop Error: Retrieving the COM class factory for component with CLSID {X.X} failed due to the following error: 80080005

receiving an Interop error from an IIS hosted web application on this line:

Application xlApp = new Microsoft.Office.Interop.Excel.Application();

The error being given is the following:

System.Runtime.InteropServices.COMException
  HResult=0x80080005
  Message=Retrieving the COM class factory for component with CLSID {00024500-0000-0000-C000-000000000046} failed due to the following error: 80080005 Server execution failed (Exception from HRESULT: 0x80080005 (CO_E_SERVER_EXEC_FAILURE)).
  Source=mscorlib
  StackTrace:
   at System.Runtime.Remoting.RemotingServices.AllocateUninitializedObject(RuntimeType objectType)
   at System.Runtime.Remoting.Activation.ActivationServices.CreateInstance(RuntimeType serverType)
   at System.Runtime.Remoting.Activation.ActivationServices.IsCurrentContextOK(RuntimeType serverType, Object[] props, Boolean bNewObj)
   at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
   at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
   at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)
   at System.Activator.CreateInstance(Type type, Boolean nonPublic)
   at System.Activator.CreateInstance(Type type)

Has anyone encountered this issue and managed to resolve it? This issue cropped up when upgrading to Office ProPlus.