diff --git a/AsbCloudApp/Requests/MessageRequest.cs b/AsbCloudApp/Requests/MessageRequest.cs
index d352f4f7..8f7f06f6 100644
--- a/AsbCloudApp/Requests/MessageRequest.cs
+++ b/AsbCloudApp/Requests/MessageRequest.cs
@@ -1,8 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace AsbCloudApp.Requests
 {
@@ -10,7 +7,7 @@ namespace AsbCloudApp.Requests
     /// <summary>
     /// параметры для запроса списка сообщений
     /// </summary>
-    public class MessageRequestBase: RequestBase
+    public class MessageRequestBase : RequestBase
     {
         /// <summary>
         /// категория
@@ -26,7 +23,7 @@ namespace AsbCloudApp.Requests
         /// <summary>
         /// конечная дата
         /// </summary>
-        public DateTime? End { get; set; } 
+        public DateTime? End { get; set; }
 
         /// <summary>
         /// строка поиска
@@ -38,7 +35,8 @@ namespace AsbCloudApp.Requests
     /// <summary>
     /// параметры для запроса списка сообщений (с id скважины)
     /// </summary>
-    public class MessageRequest: MessageRequestBase {
+    public class MessageRequest : MessageRequestBase
+    {
 
         /// <summary>
         /// id скважины
diff --git a/AsbCloudInfrastructure/Services/SAUB/MessageService.cs b/AsbCloudInfrastructure/Services/SAUB/MessageService.cs
index fe195fea..cd4a1749 100644
--- a/AsbCloudInfrastructure/Services/SAUB/MessageService.cs
+++ b/AsbCloudInfrastructure/Services/SAUB/MessageService.cs
@@ -13,6 +13,7 @@ using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 
+#nullable enable
 namespace AsbCloudInfrastructure.Services.SAUB
 {
     public class MessageService : IMessageService
@@ -28,16 +29,21 @@ namespace AsbCloudInfrastructure.Services.SAUB
 
         public async Task<PaginationContainer<MessageDto>> GetMessagesAsync(MessageRequest request, CancellationToken token)
         {
+            var result = new PaginationContainer<MessageDto>
+            {
+                Skip = request.Skip ?? 0,
+                Take = request.Take ?? 32,
+            };
 
             var idTelemetry = telemetryService.GetOrDefaultIdTelemetryByIdWell(request.IdWell);
             if (idTelemetry is null)
-                return null;
+                return result;
 
             var allEvents = await db.TelemetryEvents.FromCacheAsync(token);
             var events = allEvents.Where(e => e.IdTelemetry == idTelemetry);
 
             if (!events.Any())
-                return null;
+                return result;
 
             var query = db.TelemetryMessages.Where(m => m.IdTelemetry == idTelemetry)
                 .OrderBy(m => m.DateTime).AsNoTracking();
@@ -53,7 +59,7 @@ namespace AsbCloudInfrastructure.Services.SAUB
                 var eventIds = events.Select(e => e.IdEvent);
 
                 if (!eventIds.Any())
-                    return null;
+                    return result;
 
                 query = query.Where(m => eventIds.Contains(m.IdEvent));
             }
@@ -62,31 +68,26 @@ namespace AsbCloudInfrastructure.Services.SAUB
 
             var timezone = telemetryService.GetTimezone(idTelemetry ?? default);
 
-            if (request.Begin != default)
+            if (request.Begin is not null)
             {
                 var beginUtc = request.Begin.Value.ToUtcDateTimeOffset(timezone.Hours);
                 query = query.Where(m => m.DateTime >= beginUtc);
             }
 
-            if (request.End != default)
+            if (request.End is not null)
             {
                 var endUtc = request.End.Value.ToUtcDateTimeOffset(timezone.Hours);
                 query = query.Where(m => m.DateTime <= endUtc);
             }
 
-            var result = new PaginationContainer<MessageDto>
-            {
-                Skip = request.Skip ?? 0,
-                Take = request.Take ?? 32,
-                Count = query.Count()
-            };
+            result.Count = query.Count();
 
             if (request.SortFields?.Any() == true)
             {
                 query = query.SortBy(request.SortFields);
             }
-            var messagesList = await query.Skip(request.Skip ?? 0)
-                    .Take(request.Take ?? 32).AsNoTracking()
+            var messagesList = await query.Skip(result.Skip)
+                    .Take(result.Take).AsNoTracking()
                     .ToListAsync(token).ConfigureAwait(false);
 
             if (messagesList.Count == 0)
@@ -95,8 +96,8 @@ namespace AsbCloudInfrastructure.Services.SAUB
             var allUsers = await db.TelemetryUsers.FromCacheAsync(token);
             var users = allUsers.Where(u => u.IdTelemetry == idTelemetry);
 
-            var eventsDict = events.GroupBy(x => x.IdEvent).ToDictionary(x => x.Key, x => x.FirstOrDefault());
-            var usersDict = users.GroupBy(x => x.IdUser).ToDictionary(x => x.Key, x => x.FirstOrDefault());
+            var eventsDict = events.ToDictionary(x=>x.IdEvent, x => x);
+            var usersDict = users.ToDictionary(x => x.IdUser, x => x);
 
             foreach (var message in messagesList)
             {
@@ -110,7 +111,7 @@ namespace AsbCloudInfrastructure.Services.SAUB
 
                 if (message.IdTelemetryUser is not null)
                 {
-                    if (usersDict.TryGetValue((int)message.IdTelemetryUser, out TelemetryUser user))
+                    if (usersDict.TryGetValue((int)message.IdTelemetryUser, out TelemetryUser? user))
                     {
                         messageDto.User = user.MakeDisplayName();
                     }
@@ -118,7 +119,7 @@ namespace AsbCloudInfrastructure.Services.SAUB
                         messageDto.User = message.IdTelemetryUser.ToString();
                 }
 
-                if (eventsDict.TryGetValue(message.IdEvent, out TelemetryEvent e))
+                if (eventsDict.TryGetValue(message.IdEvent, out TelemetryEvent? e))
                 {
                     messageDto.CategoryId = e.IdCategory;
                     messageDto.Message = e.MakeMessageText(message);
@@ -134,7 +135,7 @@ namespace AsbCloudInfrastructure.Services.SAUB
             CancellationToken token = default)
         {
             if (!dtos.Any())
-                return null;
+                return Task.CompletedTask;
 
             var telemetryId = telemetryService.GetOrCreateTelemetryIdByUid(uid);
             var timezone = telemetryService.GetTimezone(telemetryId);
@@ -152,3 +153,4 @@ namespace AsbCloudInfrastructure.Services.SAUB
         }
     }
 }
+#nullable disable