render missing thread root

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/app.js b/lib/app.js
index 530f10f..c4683d7 100644
--- a/lib/app.js
+++ b/lib/app.js
@@ -55,7 +55,7 @@ App.prototype.error = console.error.bind(console, logPrefix)
 
 App.prototype.unboxMsg = function (msg, cb) {
   var self = this
-  var c = msg.value.content
+  var c = msg.value && msg.value.content
   if (typeof c !== 'string') cb(null, msg)
   else self.unboxContent(c, function (err, content) {
     if (err) {