file_manager.lua:31: attempt to index local 'counter_table' (a nil value)
stack traceback:
  /opt/kepler/share/lua/5.1/cgilua.lua:153: in function
  file_manager.lua:31: in function 'update_file_counter'
  pdf_counter.lp:14: in function 'prog'
  /opt/kepler/share/lua/5.1/cgilua/lp.lua:129: in function 'include'
  /opt/kepler/share/lua/5.1/cgilua.lua:265: in function
  (tail call): ?
  (tail call): ?
  [C]: in function 'xpcall'
  /opt/kepler/share/lua/5.1/cgilua.lua:161: in function 'pcall'
  /opt/kepler/share/lua/5.1/cgilua.lua:607: in function
  [C]: in function 'pcall'
  launcher/mod2/mod2.lua:31: in main chunk