Exchange 2013 Indexing problem - ContentIndexState Failed

Greetings Everyone,

I am running an Exchange server 2013 RTM on a Windows Server 2012. There are three databases and all of them are in a "Failed" state. I have tried all the recommendations I could find. There is no DAG configured in my case.
The databases are on two separate volumes, one has 20GB free and the other 150GB.
I have uninstalled the anti-virus just in case.

I have stopped:

Microsoft Exchange Search Host Controller
Microsoft Exchange Search

Deleted the index containing folder, started the services again and from "Failed", ContentIndexState went to "Healthy" in less than a minute. It did not even go through the crawling state. After another minute it went back to "Failed" state. Every now and then I check what the state of the Indexing is and it seem to switch between "Failed" and "Healthy" every 5 minutes or so.
Performance monitor does not show any activity on the "Crawler - Mailboxes Remaining" counter.

I have tried to add the "ContentSubmitters" group, but apparently someone has already did that. I deleted it anyway and re-created it, giving the mentioned privileges to Administrators and NetworkService. As expected, nothing changed.

I also tried dismounting and re-mounting the databases. There are no entries in the Event Log other than the standard ones indicating indexing problem. I will add them to the end of this post.

Initially, there were also problems with the DFS Replication:
"The DFS Replication service stopped replication on volume C:. This occurs when a DFSR JET database is not shut down cleanly and Auto Recovery is disabled."

I have fixed this and many of the warnings and errors stopped appearing in the Event Log. This seem to be the only thing left to be fixed aside from updating Exchange to CU11. Would it be a good idea at all to update exchange before fixing the indexing issue?
Could that be some sort of corruption in the databases? All of them are mounting fine. Please let me know if you have any recommendations as to what more can be done to pinpoint the cause of this.

Here are the messages from the log:

Event ID: 1010

An operation attempted against a FAST endpoint exprienced an exception. This operation may be retried. Error details: Microsoft.Exchange.Search.Fast.PerformingFastOperationException: An Exception was received during a FAST operation. ---> System.ServiceModel.FaultException: Invocation of method GetFlows failed on all available service instances.

Server stack trace:
   at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]:
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.Ceres.ContentEngine.Admin.FlowService.IFlowServiceManagementAgent.GetFlows()
   at Microsoft.Exchange.Search.Fast.IndexManager.<GetFlows>b__16()
   at Microsoft.Exchange.Search.Fast.IndexManagementClient.PerformFastOperation[T](Func`1 function, String eventLogKey)
   --- End of inner exception stack trace ---

The indexing of mailbox database Mailstore encountered an unexpected exception. Error details: Microsoft.Exchange.Search.Core.Abstraction.OperationFailedException: The component operation has failed. ---> Microsoft.Exchange.Search.Fast.FastConnectionException: Connection to the Content Submission Service has failed.
   at Microsoft.Exchange.Search.Fast.FastFeeder.Initialize()
   at Microsoft.Exchange.Search.Fast.Factory.InternalCreateFastFeeder(ISearchServiceConfig config, String indexSystemFlow, String indexSystemName, String instanceName, Int32 numberOfSessions)
   at Microsoft.Exchange.Search.Fast.FeederStateStorage.SendWatermarkUpdateToFast(Int64 fastId, Int64 watermark)
   at Microsoft.Exchange.Search.Fast.FeederStateStorage.SetMailboxCrawlerState(MailboxCrawlerState state)
   at Microsoft.Exchange.Search.Mdb.FeederStateInitializer.EnsureInitialStateSet()
   at Microsoft.Exchange.Search.Engine.SearchFeedingController.InternalExecutionStart()
   at Microsoft.Exchange.Search.Core.Common.Executable.InternalExecutionStart(Object state)
   --- End of inner exception stack trace ---
   at Microsoft.Exchange.Search.Core.Common.Executable.EndExecute(IAsyncResult asyncResult)
   at Microsoft.Exchange.Search.Engine.SearchRootController.ExecuteComplete(IAsyncResult asyncResult)

Indexing state not found in FAST catalog for MDB AD82B7D3-CAE9-47F2-9AB8-7F5142B9807D12.