Is it possible to do this without the warning?

[Peter Terpstra]

Dear people,
lilypond file is:
\version "2.18.2"

global = {
  \time 3/8
}

% 1: highest
classicalGuitarVoiceOne = \relative c' {
  \global
  
  d4 d8 | e4 e8 
}
% 2: lowest
classicalGuitarVoiceTwo = \relative c {
  \global
  b4. | b
}
% second highest
classicalGuitarVoiceThree = \relative c' {
  \global
  \stemNeutral \override NoteColumn.force-hshift = #0
   d16 [g,]\stemUp g8\stemDown d' | e16 [g,]\stemUp g8\stemDown e'
  
}
% 4: second lowest
classicalGuitarVoiceFour = \relative c' {
  \global
  s8 g4 | s8 g4
}

\score {
  \new Staff \with {
    midiInstrument = "acoustic guitar (nylon)"
  } { \clef "treble_8" << \classicalGuitarVoiceOne 
                          \\ \classicalGuitarVoiceTwo 
                          \\ \classicalGuitarVoiceThree 
                          \\ \classicalGuitarVoiceFour >> 
  }
 
}

Looks good but  i get the warning:
/tmp/frescobaldi-NzCKcy/tmpVlGktT/document.ly:24:20: warning: no viable initial 
configuration found: may not find 
good beam slope
   d16 [g,]\stemUp 
                   g8\stemDown d' | e16 [g,]\stemUp g8\stemDown e'
/tmp/frescobaldi-NzCKcy/tmpVlGktT/document.ly:24:53: warning: no viable initial 
configuration found: may not find 
good beam slope
   d16 [g,]\stemUp g8\stemDown d' | e16 [g,]\stemUp 
                                                    g8\stemDown e'

Thanks in advantage!

   Peter