diff --git a/tools/sandbox/rhino3dm_error/input/one_sphere.3dm b/tools/sandbox/rhino3dm_error/input/one_sphere.3dm
new file mode 100644
index 0000000..34df303
Binary files /dev/null and b/tools/sandbox/rhino3dm_error/input/one_sphere.3dm differ
diff --git a/tools/sandbox/rhino3dm_error/rhino3dm_error.js b/tools/sandbox/rhino3dm_error/rhino3dm_error.js
index 2caacfe..32cc01a 100644
--- a/tools/sandbox/rhino3dm_error/rhino3dm_error.js
+++ b/tools/sandbox/rhino3dm_error/rhino3dm_error.js
@@ -2,11 +2,17 @@ let rhino3dm = require ('../../../libs/rhino3dm.min.js')
 let fs = require ('fs');
 let path = require ('path');
 
-function GetThreeMeshesFrom3dm (rhino, rhinoFileName)
+function Open3dmFile (rhino, rhinoFileName)
 {
 	let inputBuffer = fs.readFileSync (rhinoFileName, null).buffer;
 	let inputArray = new Uint8Array (inputBuffer);
 	let inputDoc = rhino.File3dm.fromByteArray (inputArray);
+	return inputDoc;
+}
+
+function GetThreeMeshesFrom3dm (rhino, rhinoFileName)
+{
+	let inputDoc = Open3dmFile (rhino, rhinoFileName);
 	let objects = inputDoc.objects ();
 	let threeMeshes = [];
 	for (let i = 0; i < objects.count; i++) {
@@ -33,9 +39,18 @@ function WriteThreeMeshesTo3dm (rhino, threeMeshes, rhinoFileName)
 
 function ReadWriteRhinoFile (rhinoIn, rhinoOut, inputRhinoFile, outputRhinoFile)
 {
-	let threeMeshes = GetThreeMeshesFrom3dm (rhinoIn, inputRhinoFile);
-	console.log ('Meshes in ' + inputRhinoFile + ': ' + threeMeshes.length);
+	let threeMeshes = [];
+	if (inputRhinoFile !== null) {
+		threeMeshes = GetThreeMeshesFrom3dm (rhinoIn, inputRhinoFile);
+	}
+	console.log ('Meshes in ' + outputRhinoFile + ': ' + threeMeshes.length);
 	WriteThreeMeshesTo3dm (rhinoOut, threeMeshes, outputRhinoFile);
+	let reopened = Open3dmFile (rhinoIn, outputRhinoFile);
+	if (reopened !== null) {
+		console.log ('SUCCESS');
+	} else {
+		console.log ('ERROR');
+	}
 }
 
 if (!fs.existsSync ('output')){
@@ -47,5 +62,7 @@ rhino3dm ().then (async function (rhinoIn) {
 		ReadWriteRhinoFile (rhinoIn, rhinoOut, 'input/one_cube.3dm', 'output/one_cube.3dm');
 		ReadWriteRhinoFile (rhinoIn, rhinoOut, 'input/two_cubes.3dm', 'output/two_cubes.3dm');
 		ReadWriteRhinoFile (rhinoIn, rhinoOut, 'input/three_cubes.3dm', 'output/three_cubes.3dm');
+		ReadWriteRhinoFile (rhinoIn, rhinoOut, 'input/one_sphere.3dm', 'output/one_sphere.3dm');
+		ReadWriteRhinoFile (rhinoIn, rhinoOut, null, 'output/empty.3dm');
 	});
 });