I have a client/server app with the server running in a console app. Both client and server are started from VS2010 F5. Remoting over HTTP is used for communication. I believe this was running ok under .net 3.5 but I've just upgraded to .net 4.0 and now, after some random time (typically 1 minute) it throws an exception on a remoting call. The same call works fine a number of times, and then something happens, like maybe a GC, and I get this exception:

[System.Security.SecurityException] {"Request failed."} 

StackTrace from $exception:

   at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
   at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache)
   at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean skipCheckThis, Boolean fillCache)
   at System.Activator.CreateInstance(Type type, Boolean nonPublic)
   at System.Activator.CreateInstance(Type type)
   at SD.LLBLGen.Pro.ORMSupportClasses.EntityFactoryCache2.GetEntityFactory(Type factoryType)

Console app stack trace:

>   TheHub.Entities.dll!TheHub.Entities.EntityClasses.WorkflowEventEntity CreateEntityFactory() Line 487 + 0x22 bytes   C#
    SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses. EntityBase2.EntityBase2(System.Runtime.Serialization.SerializationInfo info = {System.Runtime.Serialization.SerializationInfo}, System.Runtime.Serialization.StreamingContext context = {System.Runtime.Serialization.StreamingContext}) Line 286 + 0x17 bytes C#
    TheHub.Entities.dll!TheHub.Entities.EntityClasses.CommonEntityBase. CommonEntityBase( System.Runtime.Serialization.SerializationInfo info = {System.Runtime.Serialization.SerializationInfo}, System.Runtime.Serialization.StreamingContext context = {System.Runtime.Serialization.StreamingContext}) Line 49 + 0x14 bytes C#
    TheHub.Entities.dll!TheHub.Entities.EntityClasses.WorkflowEventEntity. WorkflowEventEntity(System.Runtime.Serialization.SerializationInfo info = {System.Runtime.Serialization.SerializationInfo}, System.Runtime.Serialization.StreamingContext context = {System.Runtime.Serialization.StreamingContext}) Line 123 + 0x13 bytes   C#
    [Native to Managed Transition]  
    [Managed to Native Transition]  
    mscorlib.dll!System.Runtime.Serialization.ObjectManager.CompleteISerializableObject( object obj, System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) + 0x189 bytes  
    mscorlib.dll!System.Runtime.Serialization.ObjectManager.FixupSpecialObject( System.Runtime.Serialization.ObjectHolder holder = {System.Runtime.Serialization.ObjectHolder}) + 0x30 bytes    
    mscorlib.dll!System.Runtime.Serialization.ObjectManager.DoFixups() + 0xc2 bytes 
    mscorlib.dll!System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize( System.Runtime.Remoting.Messaging.HeaderHandler handler = {Method = {System.Reflection.RuntimeMethodInfo}}, System.Runtime.Serialization.Formatters.Binary.__BinaryParser serParser, bool fCheck, bool isCrossAppDomain, System.Runtime.Remoting.Messaging.IMethodCallMessage methodCallMessage = null) + 0xc6 bytes  
    mscorlib.dll!System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize( System.IO.Stream serializationStream, System.Runtime.Remoting.Messaging.HeaderHandler handler, bool fCheck, bool isCrossAppDomain, System.Runtime.Remoting.Messaging.IMethodCallMessage methodCallMessage) + 0xcf bytes    
    mscorlib.dll!System.Runtime.Serialization.Formatters.Binary.BinaryFormatter. UnsafeDeserialize(System.IO.Stream serializationStream, System.Runtime.Remoting.Messaging.HeaderHandler handler) + 0x11 bytes  
    System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.CoreChannel. DeserializeBinaryRequestMessage(string objectUri = "/IWorkflowService.rem", System.IO.Stream inputStream = {System.Runtime.Remoting.Channels.Http.HttpFixedLengthReadingStream}, bool bStrictBinding = false, System.Runtime.Serialization.Formatters.TypeFilterLevel securityLevel = Low) + 0x98 bytes   
    System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels. BinaryServerFormatterSink.ProcessMessage(System.Runtime.Remoting.Channels. IServerChannelSinkStack sinkStack = {System.Runtime.Remoting.Channels.ServerChannelSinkStack}, System.Runtime.Remoting.Messaging.IMessage requestMsg = null, System.Runtime.Remoting.Channels.ITransportHeaders requestHeaders = {System.Runtime.Remoting.Channels.BaseTransportHeaders}, System.IO.Stream requestStream = {System.Runtime.Remoting.Channels.Http.HttpFixedLengthReadingStream}, out System.Runtime.Remoting.Messaging.IMessage responseMsg = null, out System.Runtime.Remoting.Channels.ITransportHeaders responseHeaders = null, out System.IO.Stream responseStream = null) + 0x6ce bytes   
    System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.Http. HttpServerTransportSink.ServiceRequest(object state = {System.Runtime.Remoting.Channels.Http.HttpServerSocketHandler}) + 0x139 bytes 
    System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.SocketHandler. ProcessRequestNow() + 0x54 bytes    
    System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.RequestQueue. ProcessNextRequest(System.Runtime.Remoting.Channels.SocketHandler sh = {System.Runtime.Remoting.Channels.Http.HttpServerSocketHandler}) + 0x40 bytes 
    System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.SocketHandler .BeginReadMessageCallback(System.IAsyncResult ar = {System.Net.Sockets.OverlappedAsyncResult}) + 0xd6 bytes  
    System.dll!System.Net.LazyAsyncResult.Complete(System.IntPtr userToken) + 0x6c bytes    
    System.dll!System.Net.ContextAwareResult.CompleteCallback(object state) + 0x1a bytes    
    mscorlib.dll!System.Threading.ExecutionContext.runTryCode(object userData) + 0x51 bytes 
    [Native to Managed Transition]  
    [Managed to Native Transition]  
    mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading. ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x6a bytes   
    mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading. ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool ignoreSyncCtx) + 0x7e bytes   
    mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading. ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x2c bytes   
    System.dll!System.Net.ContextAwareResult.Complete(System.IntPtr userToken) + 0x91 bytes 
    System.dll!System.Net.LazyAsyncResult.ProtectedInvokeCallback(object result, System.IntPtr userToken) + 0xbb bytes  
    System.dll!System.Net.Sockets.BaseOverlappedAsyncResult. CompletionPortCallback( uint errorCode, uint numBytes, System.Threading.NativeOverlapped* nativeOverlapped) + 0xb5 bytes   
    mscorlib.dll!System.Threading._IOCompletionCallback.PerformIOCompletionCallback( uint errorCode, uint numBytes, System.Threading.NativeOverlapped* pOVERLAP) + 0x74 bytes   
    [Native to Managed Transition]  

Looking at the exception reveals this in m_debugString:

The action that failed was:
Demand
The type of the first permission that failed was:
System.Security.PermissionSet
The demand was for:
<PermissionSet class="System.Security.PermissionSet"
version="1"
Unrestricted="true"/>

The only permitted permissions were:
<PermissionSet class="System.Security.PermissionSet"
version="1">
<IPermission class="System.Security.Permissions.SecurityPermission, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
version="1"
Flags="SerializationFormatter"/>
</PermissionSet>

The method that caused the failure was:
System.Runtime.Remoting.Channels.ServerProcessing ProcessMessage(System.Runtime.Remoting.Channels.IServerChannelSinkStack, System.Runtime.Remoting.Messaging.IMessage, System.Runtime.Remoting.Channels.ITransportHeaders, System.IO.Stream, System.Runtime.Remoting.Messaging.IMessage ByRef, System.Runtime.Remoting.Channels.ITransportHeaders ByRef, System.IO.Stream ByRef)

My App.config for the console app looks like this:

<?xml version="1.0"?>
<configuration>
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net"/>
        <section name="dependencyInjectionInformation" type="SD.LLBLGen.Pro.ORMSupportClasses.DependencyInjectionSectionHandler, SD.LLBLGen.Pro.ORMSupportClasses.NET20, Version=3.0.0.0, Culture=neutral, PublicKeyToken=ca73b74ba4e3ff27"/>
    <section name="sqlServerCatalogNameOverwrites" type="System.Configuration.NameValueSectionHandler"/>
  </configSections>

  <appSettings>
    <add key="connectionString" value="Server=localhost;Database=TBH;User Id=xxxx;Password=xxxx"/>
    <add key="Environment" value="dev"/>
  </appSettings>

  <sqlServerCatalogNameOverwrites>
    <add key="TBH" value=""/>
  </sqlServerCatalogNameOverwrites>

  <system.runtime.remoting>
    <application>
      <channels>
        <channel ref="http" port="2223">
          <serverProviders>
            <formatter ref="binary"/>
            <provider type="ServerObjects.Remoting.ErrorLoggerSinkProvider, ServerObjects"/>
            <provider type="ServerObjects.Remoting.UserServerChannelSinkProvider, ServerObjects"/>
          </serverProviders>
        </channel>
      </channels>
    </application>
  </system.runtime.remoting>

    <dependencyInjectionInformation>
        <additionalAssemblies>
            <assembly fullName="TheHub.Shared, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
        </additionalAssemblies>
        <instanceTypeFilters>
            <instanceTypeFilter namespace="TheHub.Shared.Workflow"/>
        </instanceTypeFilters>
    </dependencyInjectionInformation>

    <log4net>
    <root>
      <level value="INFO"/>
      <appender-ref ref="ConsoleAppender"/>
      <appender-ref ref="RollingFileAppender"/>
    </root>

    <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline"/>
      </layout>
    </appender>

    <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="log.txt"/>
      <appendToFile value="true"/>
      <rollingStyle value="Size"/>
      <maxSizeRollBackups value="10"/>
      <maximumFileSize value="100KB"/>
      <staticLogFileName value="true"/>
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline"/>
      </layout>
    </appender>
  </log4net>


    <system.web>
        <httpModules>
            <add name="ASPxHttpHandlerModule" type="DevExpress.Web.ASPxClasses.ASPxHttpHandlerModule, DevExpress.Web.v10.1, Version=10.1.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"/>
        </httpModules>
    </system.web>

    <system.webServer>
        <modules>
            <add name="ASPxHttpHandlerModule" type="DevExpress.Web.ASPxClasses.ASPxHttpHandlerModule, DevExpress.Web.v10.1, Version=10.1.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"/>
        </modules>
    </system.webServer>
<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/></startup></configuration>

As you can its failing before any of my code (at least server side) so I've not posted any.

This is .Net 4 in 64bit Windows 7. LLBLGen v3.0.10.1201 . SQL Server 2008.

I have not the slightest idea where to look, sorry.

If you use adapter, could you switch on fast serialization?

I dont understand it either. I tried with fast serialization and its different in so much as it fails consistently at the same earlier point. I get 2 remoting calls successful (returning EntityCollections) and then it fails on the next one, which happens to have some prefetch details and a SortExpression. Stack trace is different to reflect the fastserializer, otherwise the error is the same:

mscorlib.dll!System.RuntimeType.CreateInstanceSlow(bool publicOnly, bool skipCheckThis, bool fillCache = true) + 0x63 bytes 
  mscorlib.dll!System.Activator.CreateInstance(System.Type type, bool nonPublic) + 0x46 bytes 
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.SerializationReader.ProcessObject(
 SD.LLBLGen.Pro.ORMSupportClasses.SerializedType typeCode = SingleInstanceType) Line 1881 + 0xd bytes C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.SerializationReader.ReadObject() Line 230 + 0x20 bytes C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.SerializationReader.ReadTokenizedObject() Line 1538 + 0x9 bytes C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.EntityCollectionBase2<TheHub.
 Entities.EntityClasses.ShipLinkCountEntity>.DeserializeOwnedData(SD.LLBLGen.Pro.ORMSupportClasses.SerializationReader reader = {SD.LLBLGen.Pro.ORMSupportClasses.SerializationReader}, object context = {System.Collections.Specialized.BitVector32}) Line 1967 + 0x11 bytes C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.EntityCollectionBase2<TheHub.
 Entities.EntityClasses.ShipLinkCountEntity>.SD.LLBLGen.Pro.ORMSupportClasses.IOwnedDataSerializable.
 DeserializeOwnedData(SD.LLBLGen.Pro.ORMSupportClasses.SerializationReader reader = {SD.LLBLGen.Pro.ORMSupportClasses.SerializationReader}, 
 object context = {System.Collections.Specialized.BitVector32}) Line 2065 C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.FastDeserializer.ReadCollection(
 SD.LLBLGen.Pro.ORMSupportClasses.IFastSerializableEntityCollection2 collection = {TheHub.Entities.HelperClasses.EntityCollection<TheHub.Entities.EntityClasses.ShipLinkCountEntity>}, System.Collections.Specialized.BitVector32 serializationFlags = {System.Collections.Specialized.BitVector32}) Line 225 C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.FastDeserializer.Deserialize(
 SD.LLBLGen.Pro.ORMSupportClasses.IFastSerializableEntityCollection2 collection = {TheHub.Entities.HelperClasses.EntityCollection<TheHub.Entities.EntityClasses.ShipLinkCountEntity>}) Line 173 C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.FastDeserializer.Deserialize(
 byte[] serializedData = {byte[147]}, object root = {TheHub.Entities.HelperClasses.EntityCollection<TheHub.Entities.EntityClasses.ShipLinkCountEntity>}) Line 91 + 0x18 bytes C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.SerializationHelper.Deserialize(
 SD.LLBLGen.Pro.ORMSupportClasses.IEntityCollection2 entityCollection = {TheHub.Entities.HelperClasses.EntityCollection<TheHub.Entities.EntityClasses.ShipLinkCountEntity>}, System.Runtime.Serialization.SerializationInfo info = {System.Runtime.Serialization.SerializationInfo}, System.Runtime.Serialization.StreamingContext context = {System.Runtime.Serialization.StreamingContext}) Line 340 C#
  SD.LLBLGen.Pro.ORMSupportClasses.NET20.dll!SD.LLBLGen.Pro.ORMSupportClasses.EntityCollectionBase2<
 TheHub.Entities.EntityClasses.ShipLinkCountEntity>.EntityCollectionBase2(System.Runtime.Serialization.SerializationInfo info = {System.Runtime.Serialization.SerializationInfo}, System.Runtime.Serialization.StreamingContext context = {System.Runtime.Serialization.StreamingContext}) Line 152 C#
> TheHub.Entities.dll!TheHub.Entities.HelperClasses.EntityCollection<TheHub.Entities.EntityClasses.
ShipLinkCountEntity>.EntityCollection(System.Runtime.Serialization.SerializationInfo info = {System.Runtime.Serialization.SerializationInfo}, System.Runtime.Serialization.StreamingContext context = {System.Runtime.Serialization.StreamingContext}) Line 90 + 0x14 bytes C#
  [Native to Managed Transition] 
  [Managed to Native Transition] 
  mscorlib.dll!System.Runtime.Serialization.ObjectManager.CompleteISerializableObject(object obj, System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) + 0x189 bytes 
  mscorlib.dll!System.Runtime.Serialization.ObjectManager.FixupSpecialObject(
 System.Runtime.Serialization.ObjectHolder holder = {System.Runtime.Serialization.ObjectHolder}) + 0x30 bytes 
  mscorlib.dll!System.Runtime.Serialization.ObjectManager.DoFixups() + 0xc2 bytes 
  mscorlib.dll!System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(
 System.Runtime.Remoting.Messaging.HeaderHandler handler = {Method = {System.Reflection.RuntimeMethodInfo}}, System.Runtime.Serialization.Formatters.Binary.__BinaryParser serParser, bool fCheck, bool isCrossAppDomain, System.Runtime.Remoting.Messaging.IMethodCallMessage methodCallMessage = null) + 0xc6 bytes 
  mscorlib.dll!System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(
 System.IO.Stream serializationStream, System.Runtime.Remoting.Messaging.HeaderHandler handler, bool fCheck, bool isCrossAppDomain, System.Runtime.Remoting.Messaging.IMethodCallMessage methodCallMessage) + 0xcf bytes 
  mscorlib.dll!System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.UnsafeDeserialize(
 System.IO.Stream serializationStream, System.Runtime.Remoting.Messaging.HeaderHandler handler) + 0x11 bytes 
  System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.CoreChannel.DeserializeBinaryRequestMessage(
 string objectUri = "/IDataService.rem", System.IO.Stream inputStream = {System.Runtime.Remoting.Channels.Http.HttpFixedLengthReadingStream}, bool bStrictBinding = false, System.Runtime.Serialization.Formatters.TypeFilterLevel securityLevel = Low) + 0x98 bytes 
  System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.BinaryServerFormatterSink.ProcessMessage(
 System.Runtime.Remoting.Channels.IServerChannelSinkStack sinkStack = {System.Runtime.Remoting.Channels.ServerChannelSinkStack}, System.Runtime.Remoting.Messaging.IMessage requestMsg = null, System.Runtime.Remoting.Channels.ITransportHeaders requestHeaders = {System.Runtime.Remoting.Channels.BaseTransportHeaders}, System.IO.Stream requestStream = {System.Runtime.Remoting.Channels.Http.HttpFixedLengthReadingStream}, out System.Runtime.Remoting.Messaging.IMessage responseMsg = null, out System.Runtime.Remoting.Channels.ITransportHeaders responseHeaders = null, out System.IO.Stream responseStream = null) + 0x6ce bytes 
  System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.Http.HttpServerTransportSink.ServiceRequest(
 object state = {System.Runtime.Remoting.Channels.Http.HttpServerSocketHandler}) + 0x139 bytes 
  System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.SocketHandler.ProcessRequestNow() + 0x54 bytes 
  System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.RequestQueue.ProcessNextRequest(
 System.Runtime.Remoting.Channels.SocketHandler sh = {System.Runtime.Remoting.Channels.Http.HttpServerSocketHandler}) + 0x40 bytes 
  System.Runtime.Remoting.dll!System.Runtime.Remoting.Channels.SocketHandler.BeginReadMessageCallback(S
 ystem.IAsyncResult ar = {System.Net.Sockets.OverlappedAsyncResult}) + 0xd6 bytes 
  System.dll!System.Net.LazyAsyncResult.Complete(System.IntPtr userToken) + 0x6c bytes 
  System.dll!System.Net.ContextAwareResult.CompleteCallback(object state) + 0x1a bytes 
  mscorlib.dll!System.Threading.ExecutionContext.runTryCode(object userData) + 0x51 bytes 
  [Native to Managed Transition] 
  [Managed to Native Transition] 
  mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, 
 System.Threading.ContextCallback callback, object state) + 0x6a bytes 
  mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, 
 System.Threading.ContextCallback callback, object state, bool ignoreSyncCtx) + 0x7e bytes 
  mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x2c bytes 
  System.dll!System.Net.ContextAwareResult.Complete(System.IntPtr userToken) + 0x91 bytes 
  System.dll!System.Net.LazyAsyncResult.ProtectedInvokeCallback(object result, System.IntPtr userToken) + 0xbb bytes 
  System.dll!System.Net.Sockets.BaseOverlappedAsyncResult.CompletionPortCallback(uint errorCode, uint numBytes,
 System.Threading.NativeOverlapped* nativeOverlapped) + 0xb5 bytes 
  mscorlib.dll!System.Threading._IOCompletionCallback.PerformIOCompletionCallback(uint errorCode, uint numBytes, 
 System.Threading.NativeOverlapped* pOVERLAP) + 0x74 bytes 
  [Native to Managed Transition] 

After several hours getting nowhere, I guess I'm not too worried: remoting seems to be deprecated in .net 4 in favour of WCF (goodbye generics and overloading :-() ) so I will switch to WCF and see if the problem just goes away.

Thanks for looking.

(please re-format stacktraces yourself next time -- Otis)

Are you doning any custom serlialization in there? Could you please attach a simple repro solution, so we can check it out?

Thanks.