From 719a5519b50c87737de9960402da6cd053f42946 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sat, 13 Feb 2016 13:01:50 +0100
Subject: [PATCH] Fix exception in HtmlControl.

---
 src/Perspex.HtmlRenderer/HtmlControl.cs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Perspex.HtmlRenderer/HtmlControl.cs b/src/Perspex.HtmlRenderer/HtmlControl.cs
index 97d7c517e5..e5e8864933 100644
--- a/src/Perspex.HtmlRenderer/HtmlControl.cs
+++ b/src/Perspex.HtmlRenderer/HtmlControl.cs
@@ -549,7 +549,11 @@ namespace Perspex.Controls.Html
                     htmlContainer.SetHtml((string) e.NewValue, control._baseCssData);
                     control.InvalidateMeasure();
                     control.InvalidateVisual();
-                    control.InvokeMouseMove();
+
+                    if (control.VisualRoot != null)
+                    {
+                        control.InvokeMouseMove();
+                    }
                 }
             }
         }