Prevented little exception

prs.desktop/Utils/CustomModuleUtils.cs

@@ -39,7 +39,7 @@ namespace PRSDesktop
                 try
                 {
                     var doc = thumbs.FirstOrDefault(x => x.ID.Equals(module.Thumbnail.ID));
-                    if (doc != null)
+                    if (doc != null && doc.Data.Length > 0)
                     {
                         var bmp = (new ImageConverter().ConvertFrom(doc.Data) as Bitmap)!;
                         image = bmp;