Question Project raised exception class 'External:SIGSEGV

function AddMaterial(aMatLib: TGlMaterialLibrary; aFileName,
  aMaterialName: string): TGlLibMaterial;
begin
  result := aMatLib.Materials.Add;
  with result do
  begin
    with Material do
    begin
      if aFileName= 'Fast_Blur' then
        begin
          MaterialOptions:= [moNoLighting];
          Texture.Disabled:= true;
          Texture.TextureMode:= tmDecal;
          BlendingMode:= bmModulate;
        end
      else
        begin
          MaterialOptions := [moIgnoreFog, moNoLighting];
          Texture.Disabled := false;
          Texture.TextureMode := tmModulate;
          BlendingMode := bmTransparency;
        end;
      with FrontProperties do
        begin
          Ambient.SetColor(1, 1, 1, 1);
          if aFileName= 'Fast_Blur' then
            Diffuse.SetColor(204,204,204,1)
          else
            Diffuse.SetColor(1, 1, 1, 1);
          Emission.SetColor(1, 1, 1, 1);
          Specular.SetColor(1, 1, 1, 1);
        end;
      Texture.ImageClassName := 'TGLCompositeImage';
      if aFileName<> 'Fast_Blur' then
        begin
          if ExtractFileExt(aFileName) = '.bmp' then
            TGLCompositeImage(Texture.Image).LoadFromFile(aFileName)
          else
            begin
              if ExtractFileExt(aFileName) = '' then
                TGLCompositeImage(Texture.Image).LoadFromFile(aFileName + '.png')
              else
                TGLCompositeImage(Texture.Image).LoadFromFile(aFileName);
            end;
        end;
    end;
    Name := aMaterialName;
  end;
end;

procedure TGLPNGImage.LoadFromFile(const filename: string);
var
  fs: TStream;
begin
  if FileStreamExists(fileName) then
  begin
    fs := CreateFileStream(fileName, fmOpenRead);
    try
      LoadFromStream(fs); //[color=#bb0044]<--- Here is i get the error when it tries to load from the Stream....[/color]
    finally
      fs.Free;
      ResourceName := filename;
    end;
  end
  else
    raise EInvalidRasterFile.CreateFmt('File %s not found', [filename]);
end;

procedure TGLPNGImage.LoadFromStream(stream: TStream);
var
  sig: array[0..7] of Byte;
  png_ptr: png_structp;
  info_ptr: png_infop;
  colorType, bitDepth: Integer;
  rowBytes: Cardinal;
  rowPointers: array of PGLUbyte;
  ii: Integer;
  use16: Boolean;
begin
  stream.Read(sig, 8);

  if _png_sig_cmp(@sig, 0, 8) <> 0 then //<--- here i get from the debugger ",msg="Cannot find bounds of current function""
    raise EInvalidRasterFile.Create('Invalid PNG file');

  png_ptr := _png_create_read_struct(ZLIB_VERSION, nil, pngErrorFn, pngWarnFn);

......

if aFileName<> 'Fast_Blur' then
        begin
          if ExtractFilePath(aFileName) = '.jpg' then
            TGLCompositeImage(Texture.Image).LoadFromFile(aFileName)