diff --git a/BeamMgr.cpp b/BeamMgr.cpp
index aff5b04..1204c2d 100644
--- a/BeamMgr.cpp
+++ b/BeamMgr.cpp
@@ -30,7 +30,7 @@ CreateBeamMgr( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_INPADV, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IBeamMgr*> ( new(nothrow) BeamMgr) ;
 }
diff --git a/EgtExchange.rc b/EgtExchange.rc
index de40419..5a2538e 100644
Binary files a/EgtExchange.rc and b/EgtExchange.rc differ
diff --git a/ExportDxf.cpp b/ExportDxf.cpp
index 41940c4..029587c 100644
--- a/ExportDxf.cpp
+++ b/ExportDxf.cpp
@@ -47,7 +47,7 @@ CreateExportDxf( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_EXPBASE, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IExportDxf*> ( new(nothrow) ExportDxf) ;
 }
diff --git a/ExportStl.cpp b/ExportStl.cpp
index 57cdade..b8ddcdc 100644
--- a/ExportStl.cpp
+++ b/ExportStl.cpp
@@ -35,7 +35,7 @@ CreateExportStl( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_EXPBASE, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IExportStl*> ( new(nothrow) ExportStl) ;
 }
diff --git a/ExportSvg.cpp b/ExportSvg.cpp
index c756fdb..f295b37 100644
--- a/ExportSvg.cpp
+++ b/ExportSvg.cpp
@@ -42,7 +42,7 @@ CreateExportSvg( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_EXPBASE, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IExportSvg*> ( new(nothrow) ExportSvg) ;
 }
diff --git a/ImportBtl.cpp b/ImportBtl.cpp
index 6254dbc..f69dea8 100644
--- a/ImportBtl.cpp
+++ b/ImportBtl.cpp
@@ -70,7 +70,7 @@ CreateImportBtl( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_INPADV, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IImportBtl*> ( new(nothrow) ImportBtl) ;
 }
diff --git a/ImportCnc.cpp b/ImportCnc.cpp
index 480bb9c..ac7699f 100644
--- a/ImportCnc.cpp
+++ b/ImportCnc.cpp
@@ -53,7 +53,7 @@ CreateImportCnc( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_INPBASE, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IImportCnc*> ( new(nothrow) ImportCnc) ;
 }
diff --git a/ImportCsf.cpp b/ImportCsf.cpp
index 4dcc8ff..cbe42bb 100644
--- a/ImportCsf.cpp
+++ b/ImportCsf.cpp
@@ -63,7 +63,7 @@ CreateImportCsf( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_INPBASE, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IImportCsf*> ( new(nothrow) ImportCsf) ;
 }
diff --git a/ImportDxf.cpp b/ImportDxf.cpp
index 1e3e12f..ae03a6e 100644
--- a/ImportDxf.cpp
+++ b/ImportDxf.cpp
@@ -31,7 +31,7 @@ CreateImportDxf( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_INPBASE, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IImportDxf*> ( new(nothrow) ImportDxf) ;
 }
diff --git a/ImportPnt.cpp b/ImportPnt.cpp
index 56b60dd..93c9e39 100644
--- a/ImportPnt.cpp
+++ b/ImportPnt.cpp
@@ -29,7 +29,7 @@ CreateImportPnt( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_INPBASE, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IImportPnt*> ( new(nothrow) ImportPnt) ;
 }
diff --git a/ImportStl.cpp b/ImportStl.cpp
index 31fb5e0..3b39c41 100644
--- a/ImportStl.cpp
+++ b/ImportStl.cpp
@@ -35,7 +35,7 @@ CreateImportStl( void)
 {
   // verifico la chiave e le opzioni
    if ( ! TestKeyForEEx( GetEExKey(), KEYOPT_EEX_INPBASE, GetEExLogger()))
-      return false ;
+      return nullptr ;
   // creo l'oggetto
    return static_cast<IImportStl*> ( new(nothrow) ImportStl) ;
 }