[Geopak SS3] .NET Framework error: Attempted to read or write protected memory

This occurred the latest time I attempted to specify the dynamic cross section to view. It was working just great the many times that preceded this attempt.

************** Exception Text **************
System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at mdlModelRef_createWorking(DgnModelRef** , DgnFile* , Int32 , Int32 , Int32 )
   at Bentley.Civil.Model.MSPlugIn.geometricModelElementRef_getThreeDModelInfo(IElementRef* geometricModelElementRef, SpaceModelElementRef* spaceRef)
   at Bentley.Civil.Model.MSPlugIn.modelElementRef_getThreeDSpaceModelElementRef(IElementRef* modelElementRef, SpaceModelElementRef* threeDSpaceElementRef)
   at Bentley.Civil.Model.MSPlugIn.GetModelGroupFromDgnCache(DgnCache* dgnCache, DgnCache** planCache, SpaceModelElementRef* threeDRef)
   at Bentley.Civil.Model.MSPlugIn.GetModelGroupFromRootModel(DgnCache** planCache, SpaceModelElementRef* threeDRef)
   at Bentley.Civil.Model.MSPlugIn.ModelManager.AutoDetachReferences()
   at Bentley.Civil.Model.MSPlugIn.ModelManager.CheckReferencesFromQueue()
   at Bentley.Civil.Model.MSPlugIn.AddIn.AutoAttachReferences(String unparsed)
   at Bentley.Internal.MicroStation.CoreHook.DispatchNoHandler(UInt32* argStack, UInt32 mysp, IntPtr pFunc)
   at Bentley.Internal.MicroStation.CoreHook.Dispatch(UInt32* argStack, UInt32 mysp, IntPtr pFunc)

Geopak SS3 .722