diff --git a/src/Api/Controllers/ConfigController.cs b/src/Api/Controllers/ConfigController.cs
index 8fb7841..dbc3eb1 100644
--- a/src/Api/Controllers/ConfigController.cs
+++ b/src/Api/Controllers/ConfigController.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
@@ -7,6 +8,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Logging;
 using TransmissionRssManager.Core;
+using TransmissionRssManager.Services;
 
 namespace TransmissionRssManager.Api.Controllers
 {
@@ -178,20 +180,20 @@ namespace TransmissionRssManager.Api.Controllers
                         Enabled = false,
                         ExtractArchives = true,
                         OrganizeMedia = true,
-                        MinimumSeedRatio = 1.0f,
-                        MediaExtensions = new[] { ".mp4", ".mkv", ".avi", ".mov", ".wmv", ".m4v", ".mpg", ".mpeg", ".flv", ".webm" },
+                        MinimumSeedRatio = 1,
+                        MediaExtensions = new List<string> { ".mp4", ".mkv", ".avi", ".mov", ".wmv", ".m4v", ".mpg", ".mpeg", ".flv", ".webm" },
                         AutoOrganizeByMediaType = true,
                         RenameFiles = false,
                         CompressCompletedFiles = false,
                         DeleteCompletedAfterDays = 0
                     },
-                    UserPreferences = new UserPreferencesConfig
+                    UserPreferences = new UserPreferences
                     {
                         EnableDarkMode = true,
                         AutoRefreshUIEnabled = true,
                         AutoRefreshIntervalSeconds = 30,
                         NotificationsEnabled = true,
-                        NotificationEvents = new[] { "torrent-added", "torrent-completed", "torrent-error" },
+                        NotificationEvents = new List<string> { "torrent-added", "torrent-completed", "torrent-error" },
                         DefaultView = "dashboard",
                         ConfirmBeforeDelete = true,
                         MaxItemsPerPage = 25,
diff --git a/src/Api/Controllers/TorrentsController.cs b/src/Api/Controllers/TorrentsController.cs
index 66e9bcf..10ac986 100644
--- a/src/Api/Controllers/TorrentsController.cs
+++ b/src/Api/Controllers/TorrentsController.cs
@@ -83,7 +83,7 @@ namespace TransmissionRssManager.Api.Controllers
 
     public class AddTorrentRequest
     {
-        public string Url { get; set; }
-        public string DownloadDir { get; set; }
+        public string Url { get; set; } = string.Empty;
+        public string DownloadDir { get; set; } = string.Empty;
     }
 }
\ No newline at end of file
diff --git a/src/Services/ConfigService.cs b/src/Services/ConfigService.cs
index 1e1936f..cdc75e7 100644
--- a/src/Services/ConfigService.cs
+++ b/src/Services/ConfigService.cs
@@ -17,7 +17,7 @@ namespace TransmissionRssManager.Services
     {
         private readonly ILogger<ConfigService> _logger;
         private readonly string _configFilePath;
-        private AppConfig _cachedConfig;
+        private AppConfig? _cachedConfig;
         private readonly object _lockObject = new object();
 
         public ConfigService(ILogger<ConfigService> logger)
@@ -407,9 +407,9 @@ namespace TransmissionRssManager.Services
                     Enabled = false,
                     ExtractArchives = true,
                     OrganizeMedia = true,
-                    MinimumSeedRatio = 1.0f
+                    MinimumSeedRatio = 1
                 },
-                UserPreferences = new UserPreferencesConfig
+                UserPreferences = new UserPreferences
                 {
                     EnableDarkMode = true,
                     AutoRefreshUIEnabled = true,
@@ -436,10 +436,10 @@ namespace TransmissionRssManager.Services
                 Enabled = false,
                 ExtractArchives = true,
                 OrganizeMedia = true,
-                MinimumSeedRatio = 1.0f
+                MinimumSeedRatio = 1
             };
 
-            config.UserPreferences ??= new UserPreferencesConfig
+            config.UserPreferences ??= new UserPreferences
             {
                 EnableDarkMode = true,
                 AutoRefreshUIEnabled = true,
diff --git a/src/Services/MetricsService.cs b/src/Services/MetricsService.cs
index 91ba461..ce45fa4 100644
--- a/src/Services/MetricsService.cs
+++ b/src/Services/MetricsService.cs
@@ -95,8 +95,12 @@ namespace TransmissionRssManager.Services
                 {
                     try
                     {
-                        var driveInfo = new System.IO.DriveInfo(System.IO.Path.GetPathRoot(downloadDir));
-                        availableSpace = driveInfo.AvailableFreeSpace;
+                        var root = System.IO.Path.GetPathRoot(downloadDir);
+                        if (!string.IsNullOrEmpty(root))
+                        {
+                            var driveInfo = new System.IO.DriveInfo(root);
+                            availableSpace = driveInfo.AvailableFreeSpace;
+                        }
                     }
                     catch (Exception ex)
                     {
diff --git a/src/Services/PostProcessor.cs b/src/Services/PostProcessor.cs
index 8a60939..677b4da 100644
--- a/src/Services/PostProcessor.cs
+++ b/src/Services/PostProcessor.cs
@@ -119,9 +119,16 @@ namespace TransmissionRssManager.Services
                 {
                     _logger.LogInformation($"Extracting archive: {archiveFile}");
                     
-                    var extractDir = Path.Combine(
-                        Path.GetDirectoryName(archiveFile),
-                        Path.GetFileNameWithoutExtension(archiveFile));
+                    var dirName = Path.GetDirectoryName(archiveFile);
+                    var fileName = Path.GetFileNameWithoutExtension(archiveFile);
+                    
+                    if (dirName == null)
+                    {
+                        _logger.LogWarning($"Could not get directory name for archive: {archiveFile}");
+                        continue;
+                    }
+                    
+                    var extractDir = Path.Combine(dirName, fileName);
                         
                     if (!Directory.Exists(extractDir))
                     {