diff --git a/LuaLibs/CalcSlices.lua b/LuaLibs/CalcSlices.lua
index cec45bf..2bcdd5c 100644
--- a/LuaLibs/CalcSlices.lua
+++ b/LuaLibs/CalcSlices.lua
@@ -876,6 +876,10 @@ local function MultiPlanarSlicing( nStmId, dMaxH, vSlicingDir, vSlicingPnt)
          end
       end
       nCnt = i + 1
+      -- aggiornamento progress
+      if EgtProcessEvents( 100 * i / #vSlicingPnt, 0) == 1 then
+         return nFirstGrpId, -1
+      end
    end
    return nFirstGrpId, nCnt
 end
@@ -884,14 +888,15 @@ end
 local function SlicingWithSolid( nStmId, nSlicingType, dMaxH, vSlicingVal, vSlicingDir)
 
    -- calcolo delle intersezioni
-   if EgtProcessEvents( 1, 0) == 1 then return false end
    local nLayId, nCnt
    if nSlicingType ~= SLICING_TYPE.MULTIPLANAR then
+      if EgtProcessEvents( 1, 0) == 1 then return false end
       nLayId, nCnt = EgtParPlanesSurfTmInters( ORIG(), vSlicingDir[1], vSlicingVal, nStmId, s_nPartId, GDB_RT.GLOB, TOLER)
+      if EgtProcessEvents( 100, 0) == 1 then return false end
    else
       nLayId, nCnt = MultiPlanarSlicing( nStmId, dMaxH, vSlicingDir, vSlicingVal)
+      if nCnt == -1 then return false end
    end
-   if EgtProcessEvents( 100, 0) == 1 then return false end
    
    local vPrevCen = {}
    local nLayCnt = 1