diff --git a/src/NzbDrone.Core/Indexers/TorrentRssParser.cs b/src/NzbDrone.Core/Indexers/TorrentRssParser.cs
index 610a132018..b295a8472c 100644
--- a/src/NzbDrone.Core/Indexers/TorrentRssParser.cs
+++ b/src/NzbDrone.Core/Indexers/TorrentRssParser.cs
@@ -86,6 +86,7 @@ protected virtual string GetInfoHash(XElement item)
                 }
                 catch
                 {
+                    // Invalid magnet URL format - fall through to return null
                 }
             }
 
diff --git a/src/Radarr.Http/Frontend/Mappers/CacheBreakerProvider.cs b/src/Radarr.Http/Frontend/Mappers/CacheBreakerProvider.cs
index 1ae8d8cfa6..66f77f29ca 100644
--- a/src/Radarr.Http/Frontend/Mappers/CacheBreakerProvider.cs
+++ b/src/Radarr.Http/Frontend/Mappers/CacheBreakerProvider.cs
@@ -35,7 +35,13 @@ public string AddCacheBreakerToPath(string resourceUrl)
                 return resourceUrl + "?t=" + DateTime.UtcNow.Ticks;
             }
 
-            var mapper = _diskMappers.Single(m => m.CanHandle(resourceUrl));
+            var mapper = _diskMappers.SingleOrDefault(m => m.CanHandle(resourceUrl));
+
+            if (mapper == null)
+            {
+                return resourceUrl;
+            }
+
             var pathToFile = mapper.Map(resourceUrl);
             var hash = _hashProvider.ComputeMd5(pathToFile).ToBase64();