diff --git a/source/blender/blenkernel/BKE_customdata.h b/source/blender/blenkernel/BKE_customdata.h
index f6b4240a026..1d344c6e810 100644
--- a/source/blender/blenkernel/BKE_customdata.h
+++ b/source/blender/blenkernel/BKE_customdata.h
@@ -121,9 +121,9 @@ int CustomData_number_of_layers(const struct CustomData *data, int type);
 
 /* duplicate data of a layer with flag NOFREE, and remove that flag.
  * returns the layer data */
-void *CustomData_duplicate_referenced_layer(struct CustomData *data, int type);
+void *CustomData_duplicate_referenced_layer(struct CustomData *data, const int type, const int totelem);
 void *CustomData_duplicate_referenced_layer_named(struct CustomData *data,
-												  int type, const char *name);
+												  const int type, const char *name, const int totelem);
 
 /* set the CD_FLAG_NOCOPY flag in custom data layers where the mask is
  * zero for the layer type, so only layer types specified by the mask
diff --git a/source/blender/blenkernel/intern/cdderivedmesh.c b/source/blender/blenkernel/intern/cdderivedmesh.c
index 2cf2225607e..6f088b8abf7 100644
--- a/source/blender/blenkernel/intern/cdderivedmesh.c
+++ b/source/blender/blenkernel/intern/cdderivedmesh.c
@@ -1870,7 +1870,7 @@ void CDDM_apply_vert_coords(DerivedMesh *dm, float (*vertCoords)[3])
 	int i;
 
 	/* this will just return the pointer if it wasn't a referenced layer */
-	vert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT);
+	vert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, dm->numVertData);
 	cddm->mvert = vert;
 
 	for(i = 0; i < dm->numVertData; ++i, ++vert)
@@ -1884,7 +1884,7 @@ void CDDM_apply_vert_normals(DerivedMesh *dm, short (*vertNormals)[3])
 	int i;
 
 	/* this will just return the pointer if it wasn't a referenced layer */
-	vert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT);
+	vert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, dm->numVertData);
 	cddm->mvert = vert;
 
 	for(i = 0; i < dm->numVertData; ++i, ++vert)
@@ -1899,7 +1899,7 @@ void CDDM_calc_normals(DerivedMesh *dm)
 	if(dm->numVertData == 0) return;
 
 	/* we don't want to overwrite any referenced layers */
-	cddm->mvert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT);
+	cddm->mvert = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, dm->numVertData);
 
 	/* make a face normal layer if not present */
 	face_nors = CustomData_get_layer(&dm->faceData, CD_NORMAL);
diff --git a/source/blender/blenkernel/intern/customdata.c b/source/blender/blenkernel/intern/customdata.c
index c88b21e2813..5305372402b 100644
--- a/source/blender/blenkernel/intern/customdata.c
+++ b/source/blender/blenkernel/intern/customdata.c
@@ -1404,7 +1404,7 @@ int CustomData_number_of_layers(const CustomData *data, int type)
 	return number;
 }
 
-void *CustomData_duplicate_referenced_layer(struct CustomData *data, int type)
+void *CustomData_duplicate_referenced_layer(struct CustomData *data, const int type, const int totelem)
 {
 	CustomDataLayer *layer;
 	int layer_index;
@@ -1416,7 +1416,20 @@ void *CustomData_duplicate_referenced_layer(struct CustomData *data, int type)
 	layer = &data->layers[layer_index];
 
 	if (layer->flag & CD_FLAG_NOFREE) {
-		layer->data = MEM_dupallocN(layer->data);
+		/* MEM_dupallocN won’t work in case of complex layers, like e.g.
+		 * CD_MDEFORMVERT, which has pointers to allocated data...
+		 * So in case a custom copy function is defined, use it!
+		 */
+		const LayerTypeInfo *typeInfo = layerType_getInfo(layer->type);
+
+		if(typeInfo->copy) {
+			char *dest_data = MEM_mallocN(typeInfo->size * totelem, "CD duplicate ref layer");
+			typeInfo->copy(layer->data, dest_data, totelem);
+			layer->data = dest_data;
+		}
+		else
+			layer->data = MEM_dupallocN(layer->data);
+
 		layer->flag &= ~CD_FLAG_NOFREE;
 	}
 
@@ -1424,7 +1437,7 @@ void *CustomData_duplicate_referenced_layer(struct CustomData *data, int type)
 }
 
 void *CustomData_duplicate_referenced_layer_named(struct CustomData *data,
-												  int type, const char *name)
+												  const int type, const char *name, const int totelem)
 {
 	CustomDataLayer *layer;
 	int layer_index;
@@ -1436,7 +1449,20 @@ void *CustomData_duplicate_referenced_layer_named(struct CustomData *data,
 	layer = &data->layers[layer_index];
 
 	if (layer->flag & CD_FLAG_NOFREE) {
-		layer->data = MEM_dupallocN(layer->data);
+		/* MEM_dupallocN won’t work in case of complex layers, like e.g.
+		 * CD_MDEFORMVERT, which has pointers to allocated data...
+		 * So in case a custom copy function is defined, use it!
+		 */
+		const LayerTypeInfo *typeInfo = layerType_getInfo(layer->type);
+
+		if(typeInfo->copy) {
+			char *dest_data = MEM_mallocN(typeInfo->size * totelem, "CD duplicate ref layer");
+			typeInfo->copy(layer->data, dest_data, totelem);
+			layer->data = dest_data;
+		}
+		else
+			layer->data = MEM_dupallocN(layer->data);
+
 		layer->flag &= ~CD_FLAG_NOFREE;
 	}
 
diff --git a/source/blender/modifiers/intern/MOD_solidify.c b/source/blender/modifiers/intern/MOD_solidify.c
index 347af0066c6..067d66fc82c 100644
--- a/source/blender/modifiers/intern/MOD_solidify.c
+++ b/source/blender/modifiers/intern/MOD_solidify.c
@@ -75,8 +75,8 @@ static void dm_calc_normal(DerivedMesh *dm, float (*temp_nors)[3])
 	/* we don't want to overwrite any referenced layers */
 
 	/*
-	Dosnt work here!
-	mv = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT);
+	Doesn't work here!
+	mv = CustomData_duplicate_referenced_layer(&dm->vertData, CD_MVERT, numVerts);
 	cddm->mvert = mv;
 	*/
 
diff --git a/source/blender/modifiers/intern/MOD_uvproject.c b/source/blender/modifiers/intern/MOD_uvproject.c
index acf65a56561..3146d1c9d5d 100644
--- a/source/blender/modifiers/intern/MOD_uvproject.c
+++ b/source/blender/modifiers/intern/MOD_uvproject.c
@@ -259,11 +259,12 @@ static DerivedMesh *uvprojectModifier_do(UVProjectModifierData *umd,
 		mul_mat3_m4_v3(projectors[i].ob->obmat, projectors[i].normal);
 	}
 
+	numFaces = dm->getNumFaces(dm);
+
 	/* make sure we are not modifying the original UV map */
 	tface = CustomData_duplicate_referenced_layer_named(&dm->faceData,
-			CD_MTFACE, uvname);
+			CD_MTFACE, uvname, numFaces);
 
-	
 	numVerts = dm->getNumVerts(dm);
 
 	coords = MEM_callocN(sizeof(*coords) * numVerts,
@@ -280,7 +281,6 @@ static DerivedMesh *uvprojectModifier_do(UVProjectModifierData *umd,
 			mul_project_m4_v3(projectors[0].projmat, *co);
 
 	mface = dm->getFaceArray(dm);
-	numFaces = dm->getNumFaces(dm);
 
 	/* apply coords as UVs, and apply image if tfaces are new */
 	for(i = 0, mf = mface; i < numFaces; ++i, ++mf, ++tface) {