anchor.diff:           IF ( ( InitInp%WvHiCOffS < InitInp%WvLowCOffS ) .OR. ( InitInp%WvLowCOffS < 0.0 ) ) THEN
               CALL SetErrStat( ErrID_Fatal, ' Programming Error in call to WAMIT2_Init: '//NewLine// &
                     '           WvHiCOffS must be larger than WvLowCOffS. Both must be positive.'// &
  -                  '              --> This should have been checked by the calling program.', ErrStat, ErrMsg, 'CheckInitInput')
  +                  '              --> This should have been checked by the calling program.', ErrStat, ErrMsg, RoutineName)
               CALL CleanUp
               RETURN
            END IF
  
positive.code:                ! Now we apply the FFT to the result of the sum
              CALL ApplyFFT_cx(  TmpDiffQTFForce(:),  TmpComplexArr(:), FFT_Data, ErrStatTmp )
              CALL SetErrStat(ErrStatTmp,'Error occured while applying the FFT to the second term of the difference QTF.', &
                             ErrStat,ErrMsg,'DiffQTF_InitCalc')
              IF ( ErrStat >= AbortErrLev ) THEN
                 IF (ALLOCATED(TmpData4D))        DEALLOCATE(TmpData4D,STAT=ErrStatTmp)
                 IF (ALLOCATED(DiffQTFForce))     DEALLOCATE(DiffQTFForce,STAT=ErrStatTmp)
  
negative.code:             CALL SetErrStat( ErrID_Fatal,' The highest frequency ( '//TRIM(Num2LStr(MAXVAL(NewmanAppData%Data3D%WvFreq1)))// &
                             ' rad/s for first wave period) data in '//TRIM(NewmanAppData%Filename)// &
                             ' is below the high frequency cutoff set by WvHiCOff.', &
                             ErrStat,ErrMsg,RoutineName)
           ENDIF
  
        ELSE IF ( NewmanAppData%DataIs4D ) THEN   ! only check if not 3D data. If there is 3D data, we default to using it for calculations
  