We've seen two examples of the following error in different TMS environments:
NullReferenceException : Object reference not set to an instance of an object. : Caused by NullReferenceException at Sdl.Tms.Ps.MultilingualExcel. Object reference not set to an instance of an object. : at Sdl.Tms.Ps.MultilingualExcel.PreProcessorWorker.CreateMultilingualFile(FileInfo sourceFileInfo) at Sdl.Tms.Ps.MultilingualExcel.PreProcessorWorker.Execute() at Sdl.Tms.Ps.MultilingualExcel.PreProcessor.Execute() at Sdl.Tms.MessageProcessing.WorkerRequestProcessor.ExecuteMessage()