Hi,

Our EPI 7 CMS site threw a lot (~ 3000 in 5 minutes) of "Exception occured while raising MessageReceived for message xxxx" errors. The forum previously had a thread about this but was closed after an upgrade for EPiServer.CMS.UI - version 9.6.1 - was released. Initially the problem went away after we installed the latest updates but now it happened again. Here are the full details:

Site Configuration:

Hosted on Azure with a Cloud license. Typically a multi-server setup, but during time of the error only 1 server was running.

Logger: 

EPiServer.Events.Providers.EventProvider

Message:

Exception occured while raising MessageReceived for message '5005' from ''
System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> Newtonsoft.Json.JsonSerializationException: Unable to find a constructor to use for type EPiServer.Shell.UI.Messaging.Internal.PushMessage. A class should either have a default constructor, one constructor with arguments or a constructor marked with the JsonConstructor attribute. Path 'Topic', line 1, position 9.
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateNewObject(JsonReader reader, JsonObjectContract objectContract, JsonProperty containerMember, JsonProperty containerProperty, String id, Boolean& createdFromNonDefaultCreator)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
at EPiServer.Shell.UI.Messaging.Internal.DefaultPushMessenger.EventRaised(Object sender, EventNotificationEventArgs e)
at EPiServer.Events.Clients.Event.<>c__DisplayClass38_0.b__0()
at System.Threading.Tasks.Task.Execute()
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
at System.Threading.Tasks.Task.Wait()
at EPiServer.Events.Clients.Event.Raise(Guid raiserId, Object param, EventRaiseOption raiseOption)
at EPiServer.Events.Clients.Event.RemoteEventReceived(Object sender, EventReceivedEventArgs e)
at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
at EPiServer.Events.Providers.EventProviderService.OnEventReceived(Object sender, EventReceivedEventArgs e)
--- End of inner exception stack trace ---
at EPiServer.Events.Providers.EventProviderService.OnEventReceived(Object sender, EventReceivedEventArgs e)
at EPiServer.Events.Providers.EventProviderService.Provider_OnMessageReceived(Object sender, EventMessageEventArgs e)
at EPiServer.Events.Providers.EventProvider.OnMessageReceived(EventMessageEventArgs args, Boolean suppressExceptions)
---> (Inner Exception #0) System.AggregateException: One or more errors occurred. ---> Newtonsoft.Json.JsonSerializationException: Unable to find a constructor to use for type EPiServer.Shell.UI.Messaging.Internal.PushMessage. A class should either have a default constructor, one constructor with arguments or a constructor marked with the JsonConstructor attribute. Path 'Topic', line 1, position 9.
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateNewObject(JsonReader reader, JsonObjectContract objectContract, JsonProperty containerMember, JsonProperty containerProperty, String id, Boolean& createdFromNonDefaultCreator)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.Jso

Exception:

System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> Newtonsoft.Json.JsonSerializationException: Unable to find a constructor to use for type EPiServer.Shell.UI.Messaging.Internal.PushMessage. A class should either have a default constructor, one constructor with arguments or a constructor marked with the JsonConstructor attribute. Path 'Topic', line 1, position 9.
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateNewObject(JsonReader reader, JsonObjectContract objectContract, JsonProperty containerMember, JsonProperty containerProperty, String id, Boolean& createdFromNonDefaultCreator)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
at EPiServer.Shell.UI.Messaging.Internal.DefaultPushMessenger.EventRaised(Object sender, EventNotificationEventArgs e)
at EPiServer.Events.Clients.Event.<>c__DisplayClass38_0.b__0()
at System.Threading.Tasks.Task.Execute()
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(