diff --git a/src/Mod/Mesh/App/Core/Algorithm.cpp b/src/Mod/Mesh/App/Core/Algorithm.cpp
index 8f8f97f136..e63cdc721e 100644
--- a/src/Mod/Mesh/App/Core/Algorithm.cpp
+++ b/src/Mod/Mesh/App/Core/Algorithm.cpp
@@ -763,7 +763,7 @@ bool MeshAlgorithm::FillupHole(const std::vector<PointIndex>& boundary,
         // Now we have two adjacent triangles which we check for overlaps.
         // Therefore we build a separation plane that must separate the two diametrically opposed points.
         Base::Vector3f planeNormal = rTriangle.GetNormal() % (rTriangle._aclPoints[(ref_side+1)%3]-rTriangle._aclPoints[ref_side]);
-        Base::Vector3f planeBase = rTriangle._aclPoints[ref_side];
+        Base::Vector3f planeBase = rTriangle._aclPoints[ref_side%3];
         Base::Vector3f ref_point = rTriangle._aclPoints[(ref_side+2)%3];
         Base::Vector3f tri_point = triangle._aclPoints[(tri_side+2)%3];
 
diff --git a/src/Mod/Mesh/App/Core/Decimation.cpp b/src/Mod/Mesh/App/Core/Decimation.cpp
index 19ebd694d1..b719119c2b 100644
--- a/src/Mod/Mesh/App/Core/Decimation.cpp
+++ b/src/Mod/Mesh/App/Core/Decimation.cpp
@@ -53,6 +53,8 @@ void MeshSimplify::simplify(float tolerance, float reduction)
     for (std::size_t i = 0; i < points.size(); i++) {
         Simplify::Vertex v;
         v.tstart = 0;
+        v.tcount = 0;
+        v.border = 0;
         v.p = points[i];
         alg.vertices.push_back(v);
     }
@@ -60,6 +62,8 @@ void MeshSimplify::simplify(float tolerance, float reduction)
     const MeshFacetArray& facets = myKernel.GetFacets();
     for (std::size_t i = 0; i < facets.size(); i++) {
         Simplify::Triangle t;
+        t.deleted = 0;
+        t.dirty = 0;
         for (int j = 0; j < 4; j++)
             t.err[j] = 0.0;
         for (int j = 0; j < 3; j++)
@@ -107,6 +111,8 @@ void MeshSimplify::simplify(int targetSize)
     for (std::size_t i = 0; i < points.size(); i++) {
         Simplify::Vertex v;
         v.tstart = 0;
+        v.tcount = 0;
+        v.border = 0;
         v.p = points[i];
         alg.vertices.push_back(v);
     }
@@ -114,6 +120,8 @@ void MeshSimplify::simplify(int targetSize)
     const MeshFacetArray& facets = myKernel.GetFacets();
     for (std::size_t i = 0; i < facets.size(); i++) {
         Simplify::Triangle t;
+        t.deleted = 0;
+        t.dirty = 0;
         for (int j = 0; j < 4; j++)
             t.err[j] = 0.0;
         for (int j = 0; j < 3; j++)
diff --git a/src/Mod/Mesh/App/Exporter.cpp b/src/Mod/Mesh/App/Exporter.cpp
index 3664d5705c..388b1a89bf 100644
--- a/src/Mod/Mesh/App/Exporter.cpp
+++ b/src/Mod/Mesh/App/Exporter.cpp
@@ -111,7 +111,8 @@ int Exporter::addObject(App::DocumentObject *obj, float tol)
                 it = meshCache.emplace(linked,
                         static_cast<Mesh::Feature*>(linked)->Mesh.getValue()).first;
                 it->second.setTransform(Base::Matrix4D());
-            } else {
+            }
+            else {
                 Base::PyGILStateLocker lock;
                 PyObject *pyobj = nullptr;
                 linked->getSubObject("", &pyobj, nullptr, false);
@@ -128,10 +129,14 @@ int Exporter::addObject(App::DocumentObject *obj, float tol)
                 Py_DECREF(pyobj);
             }
         }
-        MeshObject mesh(it->second);
-        mesh.transformGeometry(matrix);
-        if (addMesh(sobj->Label.getValue(), mesh))
-            ++count;
+
+        // Add a new mesh
+        if (it != meshCache.end()) {
+            MeshObject mesh(it->second);
+            mesh.transformGeometry(matrix);
+            if (addMesh(sobj->Label.getValue(), mesh))
+                ++count;
+        }
     }
     return count;
 }