diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5f4e675..6de104c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@
 ### Added
 - Subset more than one CityObject type (#9)
 - `models.Geometry.reproject()` for reprojecting dereferenced geometry boundaries
+- Read from `stdin` and save to `stdout`
+- `--suppress_msg` to suppress all messages. Required when saving to `stdout`
 
 ### Fixed
 - Subset with BBOX does not modify the input model anymore (#10)
@@ -13,15 +15,17 @@
 - `texture` and `material` are correctly removed from the geometries of the CityObjects with `textures/materials_remove`
 - `vertex-texture` is removed from the CityJSON with `textures_remove`
 - Docker image build (#77, #132)
+- Other minor fixes
 
 ### Changed
 - Export format is an argument, not an option (#35), e.g. `cjio ... export obj out.obj`
 - NumPy is a hard requirement
 - Require pyproj >= 3.0.0 (#142)
+- Refactor warnings and alert printing (#143)
 
 ## [0.7.4] - 2022-06-20
 ### Fixed
-- crash wiht new version of Click (>=8.1) (#140)
+- crash with new version of Click (>=8.1) (#140)
 ### Added
 - templates for bug reporting
 
diff --git a/cjio/convert.py b/cjio/convert.py
index 1c9579b..c800fa2 100644
--- a/cjio/convert.py
+++ b/cjio/convert.py
@@ -174,17 +174,25 @@ def to_glb(cm):
                     triList = []
                     for shell in geom['boundaries']:
                         for face in shell:
-                            tri = geom_help.triangulate_face(face, vertexlist)
-                            for t in tri:
-                                triList.append(list(t))
+                            tri, success = geom_help.triangulate_face(face, vertexlist)
+                            if success:
+                                for t in tri:
+                                    triList.append(list(t))
+                            else:
+                                # TODO: logging
+                                print(f"Failed to triangulate face in CityObject {theid}")
                     trigeom = (flatten(triList))
 
                 elif (geom['type'] == 'MultiSurface') or (geom['type'] == 'CompositeSurface'):
                     triList = []
                     for face in geom['boundaries']:
-                        tri = geom_help.triangulate_face(face, vertexlist)
-                        for t in tri:
-                            triList.append(t)
+                        tri, success = geom_help.triangulate_face(face, vertexlist)
+                        if success:
+                            for t in tri:
+                                triList.append(t)
+                        else:
+                            # TODO: logging
+                            print(f"Failed to triangulate face in CityObject {theid}")
                     trigeom = (flatten(triList))
                 flatgeom = trigeom
                 forimax.append(flatgeom)
@@ -199,7 +207,10 @@ def to_glb(cm):
                 # Need to swap the axis, because gltf uses a right-handed coordinate
                 # system. glTF defines +Y as up, +Z as forward, and -X as right;
                 # the front of a glTF asset faces +Z.
-                vtx_np[i] = np.array((vertexlist[v][1], vertexlist[v][2], vertexlist[v][0]))
+                try:
+                    vtx_np[i] = np.array((vertexlist[v][1], vertexlist[v][2], vertexlist[v][0]))
+                except IndexError as e:
+                    print(i, v)
                 vtx_idx_np[i] = i
             bin_vtx = vtx_np.astype(np.float32).tostring()
             # convert geometry indices to binary