diff --git a/Libs/CMS_CORE_Library.dll b/Libs/CMS_CORE_Library.dll
index 4f7ecbde..bacd17f5 100644
Binary files a/Libs/CMS_CORE_Library.dll and b/Libs/CMS_CORE_Library.dll differ
diff --git a/Step.Database/Controllers/AlarmsController.cs b/Step.Database/Controllers/AlarmsController.cs
index 2e47b214..87a0b57b 100644
--- a/Step.Database/Controllers/AlarmsController.cs
+++ b/Step.Database/Controllers/AlarmsController.cs
@@ -28,21 +28,27 @@ namespace Step.Database.Controllers
             dbCtx.Dispose();
         }
 
-        public List<DTOAlarmHistoricModel> GetPaginatedWithFilter(string title, List<ALARM_TYPE> types, int page, int pageSize, DateTime startDate, DateTime endDate, List<int> userIds, Dictionary<int, string> plcMessages)
+        public List<DTOAlarmHistoricModel> GetPaginatedWithFilter(string title, List<ALARM_TYPE> types, int page, int pageSize, DateTime startDate, DateTime endDate, List<int?> userIds, Dictionary<int, string> plcMessages)
         {
+            bool ifNoUser = false;
+            var index = userIds.IndexOf(-1);
+            if (userIds.IndexOf(-1) != -1)
+                ifNoUser = true;
+            
             List<int> ncAlarmDescIds = dbCtx
                 .AlarmDescriptions
                 .Where(x => x.Title.Contains(title))
                 .Select(x => x.AlarmId)
                 .ToList();
 
-            // Add Plc messages
+            // Get Plc messages ids
             List<int> plcAlarmDescIds = 
                 plcMessages
                 .Where(x => x.Value.Contains(title))
                 .Select(x => x.Key)
                 .ToList();
 
+            // Query
             var occurrencesQuery = dbCtx
                 .AlarmOccurrences
                 .OrderBy(x => x.AlarmOccurrenceId)
@@ -50,7 +56,7 @@ namespace Step.Database.Controllers
                 .Where(x =>
                     x.TimeStamp >= startDate && x.TimeStamp <= endDate // Filter by date
                     && types.Contains(x.Type) // Type
-                    && x.Users.Any(y => userIds.Any(z => z == y.UserId)) // Check user
+                    && ( (ifNoUser && x.Users.Count() == 0) || x.Users.Any(y => userIds.Any(z => z == y.UserId))) // Check user
                     && 
                     ((x.Source == ALARM_SOURCE.NC && ncAlarmDescIds.Contains(x.AlarmDescriptionId.Value)) // Check if message is contained in NC messages
                     || (x.Source == ALARM_SOURCE.PLC && plcAlarmDescIds.Contains(x.PlcMessageId.Value))) // Check if message is contained in PLC messages
@@ -61,7 +67,7 @@ namespace Step.Database.Controllers
                 .ToList();
 
             return occurrencesQuery
-                .Select(x => (DTOAlarmHistoricModel)x)
+                .Select(x => (DTOAlarmHistoricModel)x) // Convert to DTOALarmHistoricModel
                 .ToList();
         }