Central Admin shows HTTP 404 Not Found

Question

Specs:

2 WFE servers,
1 App Server
1 SQL Server

When I try to open Central Admin I get an "HTTP 404 Not Found" error. Application pool is not stopped and I am having almost the same issue with other applications. I can't open anyone of them.

I tried to open one of the applications and I got the following error in ULS logs: An exception occurred when trying to issue security token: Loading this assembly would produce a different grant set from other instances. (Exception from HRESULT: 0x80131401).

Another error I found in event viewer is: "The Execute method of job definition Microsoft.Office.Server.UserProfiles.LMTRepopulationJob (ID 319d5d0c-af4b-46a7-af89-a6a21d66b138) threw an exception. More information is included below. System.TimeoutException "

And I found this Application Error in Event viewer:

Faulting application name: w3wp.exe, version: 8.5.9600.16384, time stamp: 0x5215df96
Faulting module name: KERNELBASE.dll, version: 6.3.9600.18938, time stamp: 0x5a7ddf0a
Exception code: 0xe0434352
Fault offset: 0x0000000000008eac
Faulting process id: 0x754
Faulting application start time: 0x01d48b34da82c5fe
Faulting application path: c:\windows\system32\inetsrv\w3wp.exe
Faulting module path: C:\Windows\system32\KERNELBASE.dll
Report Id: 22f10db8-f728-11e8-80f1-00155dcb3e01
Faulting package full name: 
Faulting package-relative application ID: 

And another error:

An unhandled exception occurred and the process was terminated.

Application ID: /LM/W3SVC/1865553070/ROOT

Process ID: 1876

Exception: System.IO.FileLoadException

Message: Loading this assembly would produce a different grant set from other instances. (Exception from HRESULT: 0x80131401)

StackTrace: 
Server stack trace: 
   at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
   at System.ServiceModel.Channels.SocketConnectionInitiator.Connect(Uri uri, TimeSpan timeout)
   at System.ServiceModel.Channels.BufferedConnectionInitiator.Connect(Uri uri, TimeSpan timeout)
   at System.ServiceModel.Channels.ConnectionPoolHelper.EstablishConnection(TimeSpan timeout)
   at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at Microsoft.ApplicationServer.Caching.CacheResolverChannel.Open(TimeSpan timeout)
   at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(IMessage msg, IMessageSink replySink)

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.EndInvokeHelper(Message reqMsg, Boolean bProxyCase)
   at System.Runtime.Remoting.Proxies.RemotingProxy.Invoke(Object NotUsed, MessageData& msgData)
   at Microsoft.ApplicationServer.Caching.CacheResolverChannel.OpenDelegate.EndInvoke(IAsyncResult result)
   at Microsoft.ApplicationServer.Caching.ChannelContainer.Opened(IAsyncResult ar)
   at System.Runtime.Remoting.Messaging.AsyncResult.SyncProcessMessage(IMessage msg)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(IMessage msg, IMessageSink replySink)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()

And another one (source: .NET RunTime):

Application: w3wp.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.IO.FileLoadException
Stack:

Server stack trace: 
   at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
   at System.ServiceModel.Channels.SocketConnection.ReadCore(Byte[] buffer, Int32 offset, Int32 size, TimeSpan timeout, Boolean closing)
   at System.ServiceModel.Channels.SocketConnection.Read(Byte[] buffer, Int32 offset, Int32 size, TimeSpan timeout)
   at System.ServiceModel.Channels.ConnectionUpgradeHelper.InitiateUpgrade(StreamUpgradeInitiator upgradeInitiator, IConnection& connection, ClientFramingDecoder decoder, IDefaultCommunicationTimeouts defaultTimeouts, TimeoutHelper& timeoutHelper)
   at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.SendPreamble(IConnection connection, ArraySegment`1 preamble, TimeoutHelper& timeoutHelper)
   at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.DuplexConnectionPoolHelper.AcceptPooledConnection(IConnection connection, TimeoutHelper& timeoutHelper)
   at System.ServiceModel.Channels.ConnectionPoolHelper.EstablishConnection(TimeSpan timeout)
   at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at Microsoft.ApplicationServer.Caching.CacheResolverChannel.Open(TimeSpan timeout)
   at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(IMessage msg, IMessageSink replySink)
   at Microsoft.ApplicationServer.Caching.ChannelContainer.Opened(System.IAsyncResult)
   at System.Runtime.Remoting.Messaging.AsyncResult.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage, System.Runtime.Remoting.Messaging.IMessageSink)
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()

Answer 1

It is solved!!! I could not ever imagined this would be the solution, but here it is what solved the problem: Added the following entry in the registry:

hkeylocalmachine > software > Microsoft > .netframework. (add key)
Dword loaderoptimalization =1

Probably someone messed around with the servers as this solution was provided by a colleague here.