diff --git a/API/Schema/MangaContext/Chapter.cs b/API/Schema/MangaContext/Chapter.cs
index 87c4d8c..6a9e45f 100644
--- a/API/Schema/MangaContext/Chapter.cs
+++ b/API/Schema/MangaContext/Chapter.cs
@@ -66,14 +66,26 @@ public class Chapter : Identifiable, IComparable<Chapter>
         };
     }
 
+    
     /// <summary>
     /// Checks the filesystem if an archive at the ArchiveFilePath exists
     /// </summary>
+    /// <param name="context"></param>
+    /// <param name="token"></param>
     /// <returns>True if archive exists on disk</returns>
-    public bool CheckDownloaded()
+    /// <exception cref="KeyNotFoundException">Unable to load Chapter, Parent or Library</exception>
+    public async Task<bool> CheckDownloaded(MangaContext context, CancellationToken? token = null)
     {
+        if(await context.Chapters
+               .Include(c => c.ParentManga)
+               .ThenInclude(p => p.Library)
+               .FirstOrDefaultAsync(c => c.Key == this.Key, token??CancellationToken.None) is not { } chapter)
+            throw new KeyNotFoundException("Unable to find chapter");
+        
         //TODO Log here
-        return File.Exists(FullArchiveFilePath);
+        this.Downloaded = File.Exists(chapter.FullArchiveFilePath);
+        await context.Sync(token??CancellationToken.None);
+        return this.Downloaded;
     } 
 
     /// Placeholders:
diff --git a/API/Tranga.cs b/API/Tranga.cs
index f1114c1..395d42b 100644
--- a/API/Tranga.cs
+++ b/API/Tranga.cs
@@ -148,7 +148,7 @@ public static class Tranga
         if (RunningWorkers.TryGetValue(worker, out Task<BaseWorker[]>? task))
         {
             BaseWorker[] newWorkers = task.Result;
-            Log.Debug($"Resulted in {newWorkers.Length} new Workers.");
+            Log.Debug($"{worker} created {newWorkers.Length} new Workers.");
             AddWorkers(newWorkers);
         }
         RunningWorkers.Remove(worker, out _);
diff --git a/API/Workers/MangaDownloadWorkers/DownloadChapterFromMangaconnectorWorker.cs b/API/Workers/MangaDownloadWorkers/DownloadChapterFromMangaconnectorWorker.cs
index 09460a9..767a1c4 100644
--- a/API/Workers/MangaDownloadWorkers/DownloadChapterFromMangaconnectorWorker.cs
+++ b/API/Workers/MangaDownloadWorkers/DownloadChapterFromMangaconnectorWorker.cs
@@ -35,6 +35,14 @@ public class DownloadChapterFromMangaconnectorWorker(MangaConnectorId<Chapter> c
             Log.Error("Could not get MangaConnectorId.");
             return []; //TODO Exception?
         }
+        
+        // Check if Chapter already exists...
+        if (await mangaConnectorId.Obj.CheckDownloaded(DbContext, CancellationToken))
+        {
+            Log.Warn("Chapter already exists!");
+            return [];
+        }
+        
         if (!Tranga.TryGetMangaConnector(mangaConnectorId.MangaConnectorName, out MangaConnector? mangaConnector))
         {
             Log.Error("Could not get MangaConnector.");
diff --git a/API/Workers/PeriodicWorkers/UpdateChaptersDownloadedWorker.cs b/API/Workers/PeriodicWorkers/UpdateChaptersDownloadedWorker.cs
index 54e446a..97e3fe5 100644
--- a/API/Workers/PeriodicWorkers/UpdateChaptersDownloadedWorker.cs
+++ b/API/Workers/PeriodicWorkers/UpdateChaptersDownloadedWorker.cs
@@ -14,9 +14,19 @@ public class UpdateChaptersDownloadedWorker(TimeSpan? interval = null, IEnumerab
     protected override async Task<BaseWorker[]> DoWorkInternal()
     {
         Log.Debug("Checking chapter files...");
-        List<Chapter> chapters = await DbContext.Chapters.Include(c => c.ParentManga).ToListAsync(CancellationToken);
+        List<Chapter> chapters = await DbContext.Chapters.ToListAsync(CancellationToken);
         Log.Debug($"Checking {chapters.Count} chapters...");
-        chapters.ForEach(chapter => DbContext.Entry(chapter).Property(c => c.Downloaded).CurrentValue = chapter.CheckDownloaded());
+        chapters.ForEach(async void (chapter) =>
+        {
+            try
+            {
+                chapter.Downloaded = await chapter.CheckDownloaded(DbContext, CancellationToken);
+            }
+            catch (Exception exception)
+            {
+                Log.Error(exception);
+            }
+        });
 
         if(await DbContext.Sync(CancellationToken) is { success: false } e)
             Log.Error($"Failed to save database changes: {e.exceptionMessage}");