title: Cannot insert the OpenXmlElement "newChild"
body: <p>I have the following code but i keep getting the error 
  "Cannot insert the OpenXmlElement "newChild" because it is part of a tree"</p>
  
  <pre><code>private static Stylesheet CreateStylesheet()
      {
          Stylesheet ss = new Stylesheet();
          //ESTILO PARA CELDA F6
  
  
          Fills fill1 = new Fills();
  
          //INDEX 0
          PatternFill fill = new PatternFill() { PatternType = PatternValues.Gray125, BackgroundColor = new BackgroundColor() { Rgb = new HexBinaryValue() { Value = "#92d050" } }, ForegroundColor = new ForegroundColor() { Rgb = new HexBinaryValue() { Value = "#000000" } } };
          GradientFill gfill = new GradientFill() { Type = GradientValues.Path, Degree = 45, Left=0.2, Right= 0.8, Top=0.2, Bottom = 0.8 };
          GradientStop sfill1 = new GradientStop() { Position = 0, Color = new Color() { Theme = 0 }  };
          fill1.Append(fill);
          fill1.Append(gfill);
          fill1.Append(sfill1);
  
          //ESTILO PARA CELDA F7
  
          //INDEX 1
          PatternFill fill2 = new PatternFill() { PatternType = PatternValues.Gray125, BackgroundColor = new BackgroundColor() { Rgb = new HexBinaryValue() { Value = "#0a2060" } }, ForegroundColor = new ForegroundColor() { Rgb = new HexBinaryValue() { Value = "#000000" } } };
          GradientFill gfil2 = new GradientFill()  { Type = GradientValues.Path, Degree = 45, Left=0.2, Right= 0.8, Top=0.2, Bottom = 0.8 };
          GradientStop sfill2 = new GradientStop() { Position = 0, Color = new Color() { Theme = 0 } };
          fill1.Append(fill2);
          fill1.Append(gfil2);
          fill1.Append(sfill2);
  
  
          //ESTILO GENERAL DE ALTAS
  
          //INDEX 2
          PatternFill fill3 = new PatternFill() { PatternType = PatternValues.Gray125, BackgroundColor = new BackgroundColor() { Rgb = new HexBinaryValue() { Value = "#92d050" } }, ForegroundColor = new ForegroundColor() { Rgb = new HexBinaryValue() { Value = "#000000" } } };
          GradientFill gfil3 = new GradientFill() { Type = GradientValues.Path, Degree = 45, Left = 0.2, Right = 0.8, Top = 0.2, Bottom = 0.8 };
          GradientStop sfill3 = new GradientStop() { Position = 0, Color = new Color() { Theme = 0 } };
          fill1.Append(fill3);
          fill1.Append(gfil3);
          fill1.Append(sfill3);
  
          //ESTILO GENERAL DE ANUAL
  
          //INDEX 3
          PatternFill fill4 = new PatternFill() { PatternType = PatternValues.Gray125, BackgroundColor = new BackgroundColor() { Rgb = new HexBinaryValue() { Value = "#002060" } }, ForegroundColor = new ForegroundColor() { Rgb = new HexBinaryValue() { Value = "#000000" } } };
          GradientFill gfil4 = new GradientFill() { Type = GradientValues.Path, Degree = 45, Left = 0.2, Right = 0.8, Top = 0.2, Bottom = 0.8};
          GradientStop sfill4 = new GradientStop() { Position = 0, Color = new Color() { Theme = 0 } };
          fill1.Append(fill4);
          fill1.Append(gfil4);
          fill1.Append(sfill4);
  
  
  
          //ESTILO DE BORDE PARA INGRESAR UNA CELDA EN EL METODO ASIGNACELDA
  
          //INDEX 0
          Borders brs = new Borders();
          Border br = new Border() { BottomBorder = new BottomBorder() { Style = BorderStyleValues.Thin }, TopBorder = new TopBorder() { Style = BorderStyleValues.Thin }, LeftBorder = new LeftBorder() { Style = BorderStyleValues.Thin }, RightBorder = new RightBorder() { Style = BorderStyleValues.Thin } };
          brs.Append(br);
  
  
  
          //ALINEACIONES
  
  
          //ALINEACIÓN PARA EL CELL FORMAT DE CELDA GENERAL EN ASIGNACELDA
  
          Alignment al = new Alignment() { WrapText = true , Vertical = VerticalAlignmentValues.Center};
  
         //ALIENACIÓN PARA VALIDACION DE LFA Y LIA
          Alignment al2 = new Alignment() { WrapText = true , ShrinkToFit = true};
  
          //NUMERACIÓN
  
  
          //FORMATO DE NUMEROS NEGATIVOS / POSITIVOS
          NumberingFormats nformats = new NumberingFormats();
  
          //INDEX 0
          NumberingFormat nfor = new NumberingFormat() { FormatCode = "#,##0.00;[RED]-#,##0.00" };
          nformats.Append(nfor);
  
  
          //CELL FORMATS
  
  
          CellFormats cells = new CellFormats();
  
          //CELLFORMAT DE  ASIGNA CELDA GENERAL DE ASIGNACELDA
  
          //INDEX 0 ESTILO GENERALA DE ALTAS
          CellFormat cel = new CellFormat() {  Alignment = al , BorderId = 0  };
  
  
  
  //Here's where the error is generated
  --&gt;        CellFormat cel2 = new CellFormat() { Alignment = al , FillId =2 , BorderId = 0 };
  
  "           --- en este segmento es donde manda la expection "
  
          //INDEX 2 ESTILO  DE ANUAL
          CellFormat cel3 = new CellFormat() { Alignment = al, FillId = 3, BorderId = 0 };
  
  
          //INDEX 3 ESTILO PARA INSERTCELLSPECIAL
          CellFormat cel4 = new CellFormat() { NumberFormatId = 0 };
  
          //INDEX 4 ESTILO PARA VALIDACION LFA Y LIA
          CellFormat cel5 = new CellFormat() { Alignment = al2 };
  
          cells.Append(cel);
          cells.Append(cel2);
          cells.Append(cel3);
          cells.Append(cel4);
          cells.Append(cel5);
  
  
  
          return ss;
  
      }
  </code></pre>
  
  <p>Do you have any ideas?? I found a topic with the same error but for some reason it does not work for me. Any help is greatly appreciated. </p>