Duplicate error: expected wave name

#pragma rtGlobals=1     // Use modern global access method.
 
//-----------------  Menu Code  -----------------
Menu "Intensidad Trafico Loader"
    "Intensidad Trafico Loader",  TraficoLoader()
End
 
 
Function TraficoLoader()
// This function should load files (with the edning ".csv") from the Intensidad Trafico Ayto. Madrid
    string fileList, tempfile
    variable iFile, numFile
 
    NewPath /M="Choose folder containing Intensidad Trafico Data files (ending '.csv')" RawDataPath 
//  Index Directory
    fileList = IndexedFile(RawDataPath, -1, ".csv")
    print fileList
    
    numFile  = itemsinlist(fileList)
 
    if(datafolderexists("Intensidad_Trafico"))
        setdatafolder Intensidad_Trafico
    else
        newdatafolder /S Intensidad_Trafico
    endif
 
    For(iFile=0; iFile < numFile; iFile+=1)
        tempfile = stringfromlist(iFile, FileList)
        
        TraficoLoadDataFiles(tempfile)
    Endfor
End function
 
// -------------------------- -------------------------- -------------------------- --------------------------
    
Function TraficoLoadDataFiles(tempfile)
    string tempfile
    string ListOfWaves, WaveNm, NewNames
    variable numWaves, iWave
        
        // Names for the waves in the file
        NewNames = "idelem;fecha;identif;tipo_elem;tipo;intensidad;"
        NewNames += "ocupacion;carga;vmed;error;periodo_integracion;"
        
        if(!waveexists(idelem))
            LoadWave/J/D/A/W/B="C=1; F=8; F=-2; C=1; F=-2; C=1; C=1; C=1; C=1; F=-2; C=1;"/V={";","",1,0}/P=RawDataPath tempfile
            
            //rename the waves
            ListOfWaves = WaveList("wave*",";","")
            NumWaves = ItemsInList(NewNames)
 
            For(iWave=0; iWave<NumWaves; iWave+=1)
                wave wv1 = $stringfromlist(iWave, ListOfWaves)
                duplicate /O wv1 $stringfromlist(iWave, NewNames)
                killwaves /Z $stringfromlist(iWave, ListOfWaves)
            Endfor
 
            setdatafolder Intensidad_Trafico
 
        // If waves already exist, load into temp folder, then concatenate and delete folder
        else    
            newdatafolder /O/S temp
            LoadWave/J/D/A/W/B="C=1; F=8; F=-2; C=1; F=-2; C=1; C=1; C=1; C=1; F=-2; C=1;"/V={";","",1,0}/P=RawDataPath tempfile
 
            //rename the waves
            ListOfWaves = WaveList("wave*",";","")
            NumWaves = ItemsInList(NewNames)
 
            For(iWave=0; iWave<NumWaves; iWave+=1)
                wave wv1 = $stringfromlist(iWave, ListOfWaves)
                duplicate /O wv1 $stringfromlist(iWave, NewNames)
                killwaves /Z $stringfromlist(iWave, ListOfWaves)
            Endfor
 
 
            // Concatenate the waves
            numWaves = itemsinlist(NewNames)
            For(iWave=0; iWave < NumWaves; iWave +=1)
                WaveNm = stringfromlist(iWave, NewNames)
                wave TmpWv1 = $WaveNm
                wave TmpWv2 = ::$WaveNm
                concatenate {TmpWv1}, TmpWv2
            Endfor
            
            setdatafolder Intensidad_Trafico
            killdatafolder /Z temp
            
            // Sortwaves
            wave TempWv = $"idelem"
            Make /O/N=(numpnts(TempWv)) SortKey
            MakeIndex TempWv, SortKey
            for(iWave=0; iWave < numWaves; iWave +=1)
                WaveNm = stringfromlist(iWave, NewNames)
                wave TmpWv1 = $WaveNm
                IndexSort SortKey TmpWv1
            endfor          
            killwaves /Z  SortKey
            setdatafolder Intensidad_Trafico
        endif   
End function