Problem with miktex-2.9.6942-x64 and lualatex/luatex

Question

I am running MiKTeX 2.9 in windows 10 x64.

After making an fresh basic install with basic-miktex-2.9.6942-x64.exe (to keep the old) I run into a problem with a lualatex program. (correction of sidebearings sidebearings and precision left/right alignment)

1. With the new 2019 basic installation I get an error message

warning (node filter): error: [\directlua]:11: attempt to perform arithmetic on field 'xadvance' (a nil value)

and crash.

2. The program runs fine switching back to the previous 2018 environment.

3. I found that if I only exchange the entire directory C:\Program Files\MiKTeX 2.9\miktex with the old one (2018), while keeping everything else, the program now works.

In the new installation the exe files are dated 02-Jan-19 In the old one the exe files are dated 26-Jun-18 and 24-Jun-18

Any help?

Main lualatex code

% !TeX TS-program = lualatex


\documentclass[12pt]{article}

\RequirePackage{xcolor}

\usepackage{luacode}
\newcount\dropsidebearings
\input{drop_sidebearing.lua}

\newcommand{\hairlineiv}[1][green]{% 
  \leavevmode%
  \kern-0.1pt %
  \smash{\color{#1}\vrule height 5\baselineskip depth 5pt width 0.1pt}%
  \kern-0.1pt
}


\begin{document}  
\pagestyle{empty}  

\newcommand{\longtitles}{Long titles must be exactly aligned with the vertical green bar.}% the main title

\begin{minipage}{5in}
  \dropsidebearings=1  %turn on the effect
%   \longtitles

 \raggedleft\sffamily\fontsize{50}{60}\selectfont\bfseries \longtitles\hairlineiv
\end{minipage}

\end{document}

luatex code (file: drop_sidebearing.lua)

\begin{luacode*}

  local function drop_sidebearing(head, groupcode)
    if tex.count['dropsidebearings'] == 0 then
      return true
    end
    for n in node.traverse_id(node.id'hlist', head) do
      local char = node.has_glyph(n.head)
      if char then
        local f = font.getfont(char.font)
        if f.shared then
          local off = f.shared.rawdata.descriptions[char.char].boundingbox[1]*f.size/1000
           char.xadvance = char.xadvance - off
          char.xoffset = char.xoffset - off
        end
      end
      for ch in node.traverse_id(node.id'glyph', n.head) do
        char = ch
      end
      if char then
        local f = font.getfont(char.font)
        if f.shared then
          local desc = f.shared.rawdata.descriptions[char.char]
         char.xadvance = char.xadvance - (desc.width-desc.boundingbox[3])*f.size/1000
        end
      end
      local new_list = node.hpack(n.head, n.width, 'exactly')
      new_list.head = nil
      n.glue_order = new_list.glue_order 
      n.glue_set = new_list.glue_set
      n.glue_sign = new_list.glue_sign 
      node.free(new_list)
    end
    return true
  end
  luatexbase.add_to_callback('post_linebreak_filter', drop_sidebearing, 'Drop sidebearings after linebreaking')
\end{luacode*}