Created Unassigned: Exception occured in last dev build [773]

When open a typescript project, vs2013 prompt me a dialog that an exception log in ActivityLog.xml.

<entry>
<record>386</record>
<time>2014/03/10 02:09:27.236</time>
<type>Error</type>
<source>Editor or Editor Extension</source>
<description>System.ArgumentNullException: Value cannot be null.&#x000D;&#x000A;Parameter name: key&#x000D;&#x000A; at System.Collections.Generic.Dictionary`2.FindEntry(TKey key)&#x000D;&#x000A; at System.Collections.Generic.Dictionary`2.TryGetValue(TKey key, TValue&amp; value)&#x000D;&#x000A; at Microsoft.VisualStudio.Text.BraceCompletion.Implementation.BraceCompletionAggregator.Init()&#x000D;&#x000A; at Microsoft.VisualStudio.Text.BraceCompletion.Implementation.BraceCompletionAggregatorFactory.CreateAggregator()&#x000D;&#x000A; at Microsoft.VisualStudio.Text.BraceCompletion.Implementation.BraceCompletionManagerFactory.TextViewCreated(IWpfTextView textView)&#x000D;&#x000A; at Microsoft.VisualStudio.Text.Editor.Implementation.WpfTextView.&lt;&gt;c__DisplayClassc.&lt;BindContentTypeSpecificAssets&gt;b__9()&#x000D;&#x000A; at Microsoft.VisualStudio.Text.Utilities.GuardedOperations.CallExtensionPoint(Object errorSource, Action call)</description>
</entry>