diff --git a/LuaLibs/WProcessLapJoint.lua b/LuaLibs/WProcessLapJoint.lua
index 3a26fa3..13d764b 100644
--- a/LuaLibs/WProcessLapJoint.lua
+++ b/LuaLibs/WProcessLapJoint.lua
@@ -1377,6 +1377,7 @@ end
 
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 local function MakeSideGrooveByMill( Proc, nFacet, nRawId, b3Raw, sCustomMach, dMaxDepthOnSide, bEnablePreMill, bMachFromDn, dAng, bAsEnablePreMill, nSinglePass, bExcludeFinishing)
+   local sWarn
    -- dati della faccia principale (la più verticale)
    local ptC, vtN = EgtSurfTmFacetCenter( Proc.Id, nFacet, GDB_ID.ROOT)
    local dElev = WL.GetFaceElevation( Proc.Id, nFacet, nRawId)
@@ -1917,6 +1918,9 @@ local function MakeSideGrooveByMill( Proc, nFacet, nRawId, b3Raw, sCustomMach, d
          EgtSetOperationMode( nMchFId, false)
          return false, sErr
       end
+   else
+      sWarn = 'Warning in LapJoint : upside down groove with obtuse angle not completed'
+      EgtOutLog( sWarn)
    end
    
    -- verifico se devo lavorare anche la seconda faccia basandomi sul valore dell'angolo interno
@@ -2034,7 +2038,7 @@ local function MakeSideGrooveByMill( Proc, nFacet, nRawId, b3Raw, sCustomMach, d
       end
    end
 
-   return true
+   return true, sWarn
 end
 
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