diff --git a/Emby.Server.Implementations/Dto/DtoService.cs b/Emby.Server.Implementations/Dto/DtoService.cs
index 19902b26a0..0c0ba74533 100644
--- a/Emby.Server.Implementations/Dto/DtoService.cs
+++ b/Emby.Server.Implementations/Dto/DtoService.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 #pragma warning disable CS1591
 
 using System;
@@ -83,12 +81,12 @@ namespace Emby.Server.Implementations.Dto
         private ILiveTvManager LivetvManager => _livetvManagerFactory.Value;
 
         /// <inheritdoc />
-        public IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User user = null, BaseItem owner = null)
+        public IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User? user = null, BaseItem? owner = null)
         {
             var accessibleItems = user is null ? items : items.Where(x => x.IsVisible(user)).ToList();
             var returnItems = new BaseItemDto[accessibleItems.Count];
-            List<(BaseItem, BaseItemDto)> programTuples = null;
-            List<(BaseItemDto, LiveTvChannel)> channelTuples = null;
+            List<(BaseItem, BaseItemDto)>? programTuples = null;
+            List<(BaseItemDto, LiveTvChannel)>? channelTuples = null;
 
             for (int index = 0; index < accessibleItems.Count; index++)
             {
@@ -137,7 +135,7 @@ namespace Emby.Server.Implementations.Dto
             return returnItems;
         }
 
-        public BaseItemDto GetBaseItemDto(BaseItem item, DtoOptions options, User user = null, BaseItem owner = null)
+        public BaseItemDto GetBaseItemDto(BaseItem item, DtoOptions options, User? user = null, BaseItem? owner = null)
         {
             var dto = GetBaseItemDtoInternal(item, options, user, owner);
             if (item is LiveTvChannel tvChannel)
@@ -167,7 +165,7 @@ namespace Emby.Server.Implementations.Dto
             return dto;
         }
 
-        private static IList<BaseItem> GetTaggedItems(IItemByName byName, User user, DtoOptions options)
+        private static IList<BaseItem> GetTaggedItems(IItemByName byName, User? user, DtoOptions options)
         {
             return byName.GetTaggedItems(
                 new InternalItemsQuery(user)
@@ -177,7 +175,7 @@ namespace Emby.Server.Implementations.Dto
                 });
         }
 
-        private BaseItemDto GetBaseItemDtoInternal(BaseItem item, DtoOptions options, User user = null, BaseItem owner = null)
+        private BaseItemDto GetBaseItemDtoInternal(BaseItem item, DtoOptions options, User? user = null, BaseItem? owner = null)
         {
             var dto = new BaseItemDto
             {
@@ -292,7 +290,7 @@ namespace Emby.Server.Implementations.Dto
                 }
 
                 var path = mediaSource.Path;
-                string fileExtensionContainer = null;
+                string? fileExtensionContainer = null;
 
                 if (!string.IsNullOrEmpty(path))
                 {
@@ -316,7 +314,8 @@ namespace Emby.Server.Implementations.Dto
             }
         }
 
-        public BaseItemDto GetItemByNameDto(BaseItem item, DtoOptions options, List<BaseItem> taggedItems, User user = null)
+        /// <inheritdoc />
+        public BaseItemDto GetItemByNameDto(BaseItem item, DtoOptions options, List<BaseItem>? taggedItems, User? user = null)
         {
             var dto = GetBaseItemDtoInternal(item, options, user);
 
@@ -486,10 +485,10 @@ namespace Emby.Server.Implementations.Dto
             return images
                 .Select(p => GetImageCacheTag(item, p))
                 .Where(i => i is not null)
-                .ToArray();
+                .ToArray()!; // null values got filtered out
         }
 
-        private string GetImageCacheTag(BaseItem item, ItemImageInfo image)
+        private string? GetImageCacheTag(BaseItem item, ItemImageInfo image)
         {
             try
             {
@@ -508,7 +507,7 @@ namespace Emby.Server.Implementations.Dto
         /// <param name="dto">The dto.</param>
         /// <param name="item">The item.</param>
         /// <param name="user">The requesting user.</param>
-        private void AttachPeople(BaseItemDto dto, BaseItem item, User user = null)
+        private void AttachPeople(BaseItemDto dto, BaseItem item, User? user = null)
         {
             // Ordering by person type to ensure actors and artists are at the front.
             // This is taking advantage of the fact that they both begin with A
@@ -552,7 +551,7 @@ namespace Emby.Server.Implementations.Dto
 
             var list = new List<BaseItemPerson>();
 
-            var dictionary = people.Select(p => p.Name)
+            Dictionary<string, Person> dictionary = people.Select(p => p.Name)
                 .Distinct(StringComparer.OrdinalIgnoreCase).Select(c =>
                 {
                     try
@@ -565,9 +564,9 @@ namespace Emby.Server.Implementations.Dto
                         return null;
                     }
                 }).Where(i => i is not null)
-                .Where(i => user is null || i.IsVisible(user))
-                .DistinctBy(x => x.Name, StringComparer.OrdinalIgnoreCase)
-                .ToDictionary(i => i.Name, StringComparer.OrdinalIgnoreCase);
+                .Where(i => user is null || i!.IsVisible(user))
+                .DistinctBy(x => x!.Name, StringComparer.OrdinalIgnoreCase)
+                .ToDictionary(i => i!.Name, StringComparer.OrdinalIgnoreCase)!; // null values got filtered out
 
             for (var i = 0; i < people.Count; i++)
             {
@@ -580,7 +579,7 @@ namespace Emby.Server.Implementations.Dto
                     Type = person.Type
                 };
 
-                if (dictionary.TryGetValue(person.Name, out Person entity))
+                if (dictionary.TryGetValue(person.Name, out Person? entity))
                 {
                     baseItemPerson.PrimaryImageTag = GetTagAndFillBlurhash(dto, entity, ImageType.Primary);
                     baseItemPerson.Id = entity.Id;
@@ -650,7 +649,7 @@ namespace Emby.Server.Implementations.Dto
             return _libraryManager.GetGenreId(name);
         }
 
-        private string GetTagAndFillBlurhash(BaseItemDto dto, BaseItem item, ImageType imageType, int imageIndex = 0)
+        private string? GetTagAndFillBlurhash(BaseItemDto dto, BaseItem item, ImageType imageType, int imageIndex = 0)
         {
             var image = item.GetImageInfo(imageType, imageIndex);
             if (image is not null)
@@ -661,9 +660,14 @@ namespace Emby.Server.Implementations.Dto
             return null;
         }
 
-        private string GetTagAndFillBlurhash(BaseItemDto dto, BaseItem item, ItemImageInfo image)
+        private string? GetTagAndFillBlurhash(BaseItemDto dto, BaseItem item, ItemImageInfo image)
         {
             var tag = GetImageCacheTag(item, image);
+            if (tag is null)
+            {
+                return null;
+            }
+
             if (!string.IsNullOrEmpty(image.BlurHash))
             {
                 dto.ImageBlurHashes ??= new Dictionary<ImageType, Dictionary<string, string>>();
@@ -716,7 +720,7 @@ namespace Emby.Server.Implementations.Dto
         /// <param name="item">The item.</param>
         /// <param name="owner">The owner.</param>
         /// <param name="options">The options.</param>
-        private void AttachBasicFields(BaseItemDto dto, BaseItem item, BaseItem owner, DtoOptions options)
+        private void AttachBasicFields(BaseItemDto dto, BaseItem item, BaseItem? owner, DtoOptions options)
         {
             if (options.ContainsField(ItemFields.DateCreated))
             {
@@ -1097,7 +1101,7 @@ namespace Emby.Server.Implementations.Dto
                 }
             }
 
-            BaseItem[] allExtras = null;
+            BaseItem[]? allExtras = null;
 
             if (options.ContainsField(ItemFields.SpecialFeatureCount))
             {
@@ -1134,7 +1138,7 @@ namespace Emby.Server.Implementations.Dto
                 dto.SeasonId = episode.SeasonId;
                 dto.SeriesId = episode.SeriesId;
 
-                Series episodeSeries = null;
+                Series? episodeSeries = null;
 
                 // this block will add the series poster for episodes without a poster
                 // TODO maybe remove the if statement entirely
@@ -1162,8 +1166,10 @@ namespace Emby.Server.Implementations.Dto
             }
 
             // Add SeriesInfo
-            if (item is Series series)
+            Series? series;
+            if (item is Series tmp)
             {
+                series = tmp;
                 dto.AirDays = series.AirDays;
                 dto.AirTime = series.AirTime;
                 dto.Status = series.Status?.ToString();
@@ -1264,7 +1270,7 @@ namespace Emby.Server.Implementations.Dto
             }
         }
 
-        private BaseItem GetImageDisplayParent(BaseItem currentItem, BaseItem originalItem)
+        private BaseItem? GetImageDisplayParent(BaseItem currentItem, BaseItem originalItem)
         {
             if (currentItem is MusicAlbum musicAlbum)
             {
@@ -1285,7 +1291,7 @@ namespace Emby.Server.Implementations.Dto
             return parent;
         }
 
-        private void AddInheritedImages(BaseItemDto dto, BaseItem item, DtoOptions options, BaseItem owner)
+        private void AddInheritedImages(BaseItemDto dto, BaseItem item, DtoOptions options, BaseItem? owner)
         {
             if (!item.SupportsInheritedParentImages)
             {
@@ -1305,7 +1311,7 @@ namespace Emby.Server.Implementations.Dto
                 return;
             }
 
-            BaseItem parent = null;
+            BaseItem? parent = null;
             var isFirst = true;
 
             var imageTags = dto.ImageTags;
@@ -1378,7 +1384,7 @@ namespace Emby.Server.Implementations.Dto
             }
         }
 
-        private string GetMappedPath(BaseItem item, BaseItem ownerItem)
+        private string GetMappedPath(BaseItem item, BaseItem? ownerItem)
         {
             var path = item.Path;
 
diff --git a/Jellyfin.Api/Controllers/LiveTvController.cs b/Jellyfin.Api/Controllers/LiveTvController.cs
index 0cf36f57ec..6c3d011036 100644
--- a/Jellyfin.Api/Controllers/LiveTvController.cs
+++ b/Jellyfin.Api/Controllers/LiveTvController.cs
@@ -688,7 +688,7 @@ public class LiveTvController : BaseJellyfinApiController
             }
         }
 
-        var dtoOptions = new DtoOptions { Fields = body.Fields }
+        var dtoOptions = new DtoOptions { Fields = body.Fields ?? [] }
             .AddClientFields(User)
             .AddAdditionalDtoOptions(body.EnableImages, body.EnableUserData, body.ImageTypeLimit, body.EnableImageTypes ?? []);
         return await _liveTvManager.GetPrograms(query, dtoOptions, CancellationToken.None).ConfigureAwait(false);
diff --git a/Jellyfin.Api/Extensions/DtoExtensions.cs b/Jellyfin.Api/Extensions/DtoExtensions.cs
index 3d17dbda18..f52b58babf 100644
--- a/Jellyfin.Api/Extensions/DtoExtensions.cs
+++ b/Jellyfin.Api/Extensions/DtoExtensions.cs
@@ -26,8 +26,6 @@ public static class DtoExtensions
     internal static DtoOptions AddClientFields(
         this DtoOptions dtoOptions, ClaimsPrincipal user)
     {
-        dtoOptions.Fields ??= Array.Empty<ItemFields>();
-
         string? client = user.GetClient();
 
         // No client in claim
diff --git a/MediaBrowser.Controller/Dto/DtoOptions.cs b/MediaBrowser.Controller/Dto/DtoOptions.cs
index ecc833154d..cb638cf90b 100644
--- a/MediaBrowser.Controller/Dto/DtoOptions.cs
+++ b/MediaBrowser.Controller/Dto/DtoOptions.cs
@@ -1,5 +1,3 @@
-#nullable disable
-
 #pragma warning disable CS1591
 
 using System;