diff --git a/Implab/Implab.csproj b/Implab/Implab.csproj
--- a/Implab/Implab.csproj
+++ b/Implab/Implab.csproj
@@ -7,8 +7,6 @@
     <OutputType>Library</OutputType>
     <RootNamespace>Implab</RootNamespace>
     <AssemblyName>Implab</AssemblyName>
-    <ProductVersion>8.0.30703</ProductVersion>
-    <SchemaVersion>2.0</SchemaVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
diff --git a/Implab/JSON/JSONXmlReader.cs b/Implab/JSON/JSONXmlReader.cs
--- a/Implab/JSON/JSONXmlReader.cs
+++ b/Implab/JSON/JSONXmlReader.cs
@@ -276,7 +276,7 @@ namespace Implab.JSON {
                 if (Convert.GetTypeCode(m_parser.ElementValue) == TypeCode.Double)
                     return ((double)m_parser.ElementValue).ToString(CultureInfo.InvariantCulture);
                 else
-                    return (string)m_parser.ElementValue;
+                    return m_parser.ElementValue.ToString();
             }
         }