diff --git a/LuaLibs/CalcPaths.lua b/LuaLibs/CalcPaths.lua
index 0263858..086511b 100644
--- a/LuaLibs/CalcPaths.lua
+++ b/LuaLibs/CalcPaths.lua
@@ -643,7 +643,9 @@ end
 
 ------------------------------------------------------------------------
 local function AdjustUserLinkRibs( tUserLink, vRibs, vtSlicing, nSrfInt, nSrfExt)
-
+   
+   if nSrfInt == GDB_ID.NULL and nSrfExt == GDB_ID.NULL then return end
+   
    local nGrpTmp = EgtGroup( EgtGetParent( nSrfInt))  -- gruppo temporaneo per conti
    local vUsed = {}   -- setti di vRibs utilizzati per UserLink
    
@@ -1737,6 +1739,7 @@ local function ReassignInfo( nCrv, nCnt, vOrig)
                CopyInfo( vOrig[i], nId, KEY_ASSOCIATED_SURF, 'i')
                CopyInfo( vOrig[i], nId, KEY_RIBS_OVERLAP, 'i')
                CopyInfo( vOrig[i], nId, KEY_RIBS_TYPE, 'i')
+               CopyInfo( vOrig[i], nId, KEY_RIBS_LINK, 'b')
                bStart = true
             end
             -- verifico se corrisponde al suo end
@@ -2677,7 +2680,7 @@ function CalcPaths.Exec( nPartId)
    local LayerParams = GetLayerParamsForPathCalc()
    -- scorro tutti i suoi layer
    for nIdx = 1, #vLayIds do
-     
+
       s_nCurrIdx = nIdx
       
       local nRibsGrp = EgtGetFirstNameInGroup( vLayIds[nIdx], RIBS_GRP)