diff --git a/Controls.DocumentViewer/DocumentViewer.vb b/Controls.DocumentViewer/DocumentViewer.vb
index ae6191af..de848ea2 100644
--- a/Controls.DocumentViewer/DocumentViewer.vb
+++ b/Controls.DocumentViewer/DocumentViewer.vb
@@ -637,14 +637,17 @@ Public Class DocumentViewer
                     SpreadsheetControl1.Dock = DockStyle.Fill
 
                 Case Else
-                    GdViewer.ZoomMode = ViewerZoomMode.ZoomModeWidthViewer
-                    GdViewer.DocumentAlignment = ViewerDocumentAlignment.DocumentAlignmentTopCenter
-                    If Viewer_ForceTemporaryMode = True Then
-                        GdViewer.ForceTemporaryMode = True
-                    End If
-                    GdViewer.AnnotationDropShadow = True
+                    If Not GdViewer Is Nothing Then
+                        GdViewer.ZoomMode = ViewerZoomMode.ZoomModeWidthViewer
+                        GdViewer.DocumentAlignment = ViewerDocumentAlignment.DocumentAlignmentTopCenter
+                        If Viewer_ForceTemporaryMode = True Then
+                            GdViewer.ForceTemporaryMode = True
+                        End If
+                        GdViewer.AnnotationDropShadow = True
+
+                        GdViewer.DisplayFromStream(Stream)
+                    End If
 
-                    GdViewer.DisplayFromStream(Stream)
 
             End Select