diff --git a/LuaLibs/MachiningLib.lua b/LuaLibs/MachiningLib.lua
index d69f7f3..768a9fd 100644
--- a/LuaLibs/MachiningLib.lua
+++ b/LuaLibs/MachiningLib.lua
@@ -25,12 +25,14 @@ EgtOutLog( ' MachiningLib started', 1)
 
 -- Dati
 local BD = require( 'BeamData')
-local Cuttings = require( 'CutData')
-local Millings = require( 'MillingData')
-local Pocketings = require( 'PocketingData')
-local Sawings = require( 'SawingData')
-local Drillings = require( 'DrillData')
-local Probing = require( 'ProbingData')
+-- librerie lavorazioni caricate con pcall perchè potrebbero non esserci
+local Cuttings, Millings, Pocketings, Sawings, Drillings, Probing
+if pcall( require, 'CutData')       then   Cuttings = require( 'CutData')         end
+if pcall( require, 'MillingData')   then   Millings = require( 'MillingData')     end
+if pcall( require, 'PocketingData') then   Pocketings = require( 'PocketingData') end
+if pcall( require, 'SawingData')    then   Sawings = require( 'SawingData')       end
+if pcall( require, 'DrillData')     then   Drillings = require( 'DrillData')      end
+if pcall( require, 'ProbingData')   then   Probing = require( 'ProbingData')      end
 
 -- tipo di teste macchina
 local ONE_HEAD = 1                      -- una testa (Fast, One, Turn1T)
@@ -185,20 +187,32 @@ end
 
 ---------------------------------------------------------------------
 function GetMachinings( MachiningType, sType)
-   local Machinings
+   local Machinings = {}
    -- leggo le lavorazioni disponibili
    if MachiningType == MCH_MY.DRILLING then
-      Machinings = Drillings
+      if Drillings and type( Drillings) == "table" then
+         Machinings = Drillings
+      end
    elseif MachiningType == MCH_MY.SAWING then
-      Machinings = Cuttings
+      if Cuttings and type( Cuttings) == "table" then
+         Machinings = Cuttings
+      end
    elseif MachiningType == MCH_MY.MILLING then
-      Machinings = Millings
+      if Millings and type( Millings) == "table" then
+         Machinings = Millings
+      end
    elseif MachiningType == MCH_MY.POCKETING then
-      Machinings = Pocketings
+      if Pocketings and type( Pocketings) == "table" then
+         Machinings = Pocketings
+      end
    elseif MachiningType == MCH_MY.MORTISING then
-      Machinings = Sawings
+      if Sawings and type( Sawings) == "table" then
+         Machinings = Sawings
+      end
    elseif MachiningType == MCH_MY.PROBING then
-      Machinings = Probing
+      if Probing and type( Probing) == "table" then
+         Machinings = Probing
+      end
    end
    -- scrivo i parametri utensile nella lavorazione
    local validMachinings = {}