--- a/src/Shared/ExceptionHandling.cs

+++ b/src/Shared/ExceptionHandling.cs

@@ -153,7 +153,9 @@ namespace Microsoft.Build.Shared

         internal static bool IsXmlException(Exception e)

         {

             return e is XmlException

+#if FEATURE_SECURITY_PERMISSIONS

                 || e is XmlSyntaxException

+#endif

                 || e is XmlSchemaException

                 || e is UriFormatException; // XmlTextReader for example uses this under the covers

         }