Redownload after failure is an advanced option.

New: Handle failed downloads and attempt to find another release (SABnzbd only)

src/NzbDrone.Core/Configuration/ConfigService.cs

@@ -261,6 +261,13 @@ namespace NzbDrone.Core.Configuration
             set { SetValue("AutoDownloadPropers", value); }
         }
 
+        public Boolean AutoRedownloadFailed
+        {
+            get { return GetValueBoolean("AutoRedownloadFailed", true); }
+
+            set { SetValue("AutoRedownloadFailed", value); }
+        }
+
         public string DownloadClientWorkingFolders
         {
             get { return GetValue("DownloadClientWorkingFolders", "_UNPACK_|_FAILED_"); }

src/NzbDrone.Core/Configuration/IConfigService.cs

@@ -39,6 +39,7 @@ namespace NzbDrone.Core.Configuration
         Int32 RssSyncInterval { get; set; }
         Boolean AutoDownloadPropers { get; set; }
         String DownloadClientWorkingFolders { get; set; }
+        Boolean AutoRedownloadFailed { get; set; }
         void SaveValues(Dictionary<string, object> configValues);
     }
 }