diff --git a/red/runtime/nodes/context/localfilesystem.js b/red/runtime/nodes/context/localfilesystem.js
index dc25b6290..548c98c60 100644
--- a/red/runtime/nodes/context/localfilesystem.js
+++ b/red/runtime/nodes/context/localfilesystem.js
@@ -230,14 +230,31 @@ LocalFileSystem.prototype.get = function(scope, key, callback) {
     }
     var storagePath = getStoragePath(this.storageBaseDir ,scope);
     loadFile(storagePath + ".json").then(function(data){
+        var value;
         if(data){
             data = JSON.parse(data);
             if (!Array.isArray(key)) {
-                callback(null, util.getObjectProperty(data,key));
+                try {
+                    value = util.getObjectProperty(data,key);
+                } catch(err) {
+                    if (err.code === "INVALID_EXPR") {
+                        throw err;
+                    }
+                    value = undefined;
+                }
+                callback(null, value);
             } else {
                 var results = [undefined];
                 for (var i=0;i<key.length;i++) {
-                    results.push(util.getObjectProperty(data,key[i]))
+                    try {
+                        value = util.getObjectProperty(data,key[i]);
+                    } catch(err) {
+                        if (err.code === "INVALID_EXPR") {
+                            throw err;
+                        }
+                        value = undefined;
+                    }
+                    results.push(value)
                 }
                 callback.apply(null,results);
             }
diff --git a/red/runtime/nodes/context/memory.js b/red/runtime/nodes/context/memory.js
index 3e7f37ad1..2fa0ba7ce 100644
--- a/red/runtime/nodes/context/memory.js
+++ b/red/runtime/nodes/context/memory.js
@@ -32,7 +32,14 @@ Memory.prototype._getOne = function(scope, key) {
     var value;
     var error;
     if(this.data[scope]){
-        value = util.getObjectProperty(this.data[scope], key);
+        try {
+            value = util.getObjectProperty(this.data[scope], key);
+        } catch(err) {
+            if (err.code === "INVALID_EXPR") {
+                throw err;
+            }
+            value = undefined;
+        }
     }
     return value;
 }
diff --git a/red/runtime/util.js b/red/runtime/util.js
index d5643fcd5..b1ca7a977 100644
--- a/red/runtime/util.js
+++ b/red/runtime/util.js
@@ -130,13 +130,19 @@ function compareObjects(obj1,obj2) {
     return true;
 }
 
+function createError(code, message) {
+    var e = new Error(message);
+    e.code = code;
+    return e;
+}
+
 function normalisePropertyExpression(str) {
     // This must be kept in sync with validatePropertyExpression
     // in editor/js/ui/utils.js
 
     var length = str.length;
     if (length === 0) {
-        throw new Error("Invalid property expression: zero-length");
+        throw createError("INVALID_EXPR","Invalid property expression: zero-length");
     }
     var parts = [];
     var start = 0;
@@ -149,14 +155,14 @@ function normalisePropertyExpression(str) {
         if (!inString) {
             if (c === "'" || c === '"') {
                 if (i != start) {
-                    throw new Error("Invalid property expression: unexpected "+c+" at position "+i);
+                    throw createError("INVALID_EXPR","Invalid property expression: unexpected "+c+" at position "+i);
                 }
                 inString = true;
                 quoteChar = c;
                 start = i+1;
             } else if (c === '.') {
                 if (i===0) {
-                    throw new Error("Invalid property expression: unexpected . at position 0");
+                    throw createError("INVALID_EXPR","Invalid property expression: unexpected . at position 0");
                 }
                 if (start != i) {
                     v = str.substring(start,i);
@@ -167,57 +173,57 @@ function normalisePropertyExpression(str) {
                     }
                 }
                 if (i===length-1) {
-                    throw new Error("Invalid property expression: unterminated expression");
+                    throw createError("INVALID_EXPR","Invalid property expression: unterminated expression");
                 }
                 // Next char is first char of an identifier: a-z 0-9 $ _
                 if (!/[a-z0-9\$\_]/i.test(str[i+1])) {
-                    throw new Error("Invalid property expression: unexpected "+str[i+1]+" at position "+(i+1));
+                    throw createError("INVALID_EXPR","Invalid property expression: unexpected "+str[i+1]+" at position "+(i+1));
                 }
                 start = i+1;
             } else if (c === '[') {
                 if (i === 0) {
-                    throw new Error("Invalid property expression: unexpected "+c+" at position "+i);
+                    throw createError("INVALID_EXPR","Invalid property expression: unexpected "+c+" at position "+i);
                 }
                 if (start != i) {
                     parts.push(str.substring(start,i));
                 }
                 if (i===length-1) {
-                    throw new Error("Invalid property expression: unterminated expression");
+                    throw createError("INVALID_EXPR","Invalid property expression: unterminated expression");
                 }
                 // Next char is either a quote or a number
                 if (!/["'\d]/.test(str[i+1])) {
-                    throw new Error("Invalid property expression: unexpected "+str[i+1]+" at position "+(i+1));
+                    throw createError("INVALID_EXPR","Invalid property expression: unexpected "+str[i+1]+" at position "+(i+1));
                 }
                 start = i+1;
                 inBox = true;
             } else if (c === ']') {
                 if (!inBox) {
-                    throw new Error("Invalid property expression: unexpected "+c+" at position "+i);
+                    throw createError("INVALID_EXPR","Invalid property expression: unexpected "+c+" at position "+i);
                 }
                 if (start != i) {
                     v = str.substring(start,i);
                     if (/^\d+$/.test(v)) {
                         parts.push(parseInt(v));
                     } else {
-                        throw new Error("Invalid property expression: unexpected array expression at position "+start);
+                        throw createError("INVALID_EXPR","Invalid property expression: unexpected array expression at position "+start);
                     }
                 }
                 start = i+1;
                 inBox = false;
             } else if (c === ' ') {
-                throw new Error("Invalid property expression: unexpected ' ' at position "+i);
+                throw createError("INVALID_EXPR","Invalid property expression: unexpected ' ' at position "+i);
             }
         } else {
             if (c === quoteChar) {
                 if (i-start === 0) {
-                    throw new Error("Invalid property expression: zero-length string at position "+start);
+                    throw createError("INVALID_EXPR","Invalid property expression: zero-length string at position "+start);
                 }
                 parts.push(str.substring(start,i));
                 // If inBox, next char must be a ]. Otherwise it may be [ or .
                 if (inBox && !/\]/.test(str[i+1])) {
-                    throw new Error("Invalid property expression: unexpected array expression at position "+start);
+                    throw createError("INVALID_EXPR","Invalid property expression: unexpected array expression at position "+start);
                 } else if (!inBox && i+1!==length && !/[\[\.]/.test(str[i+1])) {
-                    throw new Error("Invalid property expression: unexpected "+str[i+1]+" expression at position "+(i+1));
+                    throw createError("INVALID_EXPR","Invalid property expression: unexpected "+str[i+1]+" expression at position "+(i+1));
                 }
                 start = i+1;
                 inString = false;
@@ -226,7 +232,7 @@ function normalisePropertyExpression(str) {
 
     }
     if (inBox || inString) {
-        throw new Error("Invalid property expression: unterminated expression");
+        throw new createError("INVALID_EXPR","Invalid property expression: unterminated expression");
     }
     if (start < length) {
         parts.push(str.substring(start));
diff --git a/test/red/runtime/nodes/context/localfilesystem_spec.js b/test/red/runtime/nodes/context/localfilesystem_spec.js
index 62028cdfe..fda5cf11d 100644
--- a/test/red/runtime/nodes/context/localfilesystem_spec.js
+++ b/test/red/runtime/nodes/context/localfilesystem_spec.js
@@ -672,7 +672,7 @@ describe('localfilesystem',function() {
 
         it('should enumerate context keys in the cache',function() {
             var globalData = {foo:"bar"};
-            fs.outputFile(path.join(resourcesDir,defaultContextBase,"global","global.json"), JSON.stringify(globalData,null,4), "utf8").then(function(){
+            return fs.outputFile(path.join(resourcesDir,defaultContextBase,"global","global.json"), JSON.stringify(globalData,null,4), "utf8").then(function(){
                 context = LocalFileSystem({dir: resourcesDir, cache: true, flushInterval: 2});
                 return context.open()
             }).then(function(){
diff --git a/test/red/runtime/nodes/context/memory_spec.js b/test/red/runtime/nodes/context/memory_spec.js
index b353fd209..61ef63cc0 100644
--- a/test/red/runtime/nodes/context/memory_spec.js
+++ b/test/red/runtime/nodes/context/memory_spec.js
@@ -96,7 +96,7 @@ describe('memory',function() {
                 context.set("nodeX","three","test3");
                 context.set("nodeX","four","test4");
 
-                var values = context.get("nodeX",["one","unknown"]);
+                var values = context.get("nodeX",["one","unknown.with.multiple.levels"]);
                 values.should.eql(["test1",undefined])
             })
             it('should throw error if bad key included in multiple keys', function() {