V8.3.1.1 crashing during file indexing

Recently, X1 is constantly crashing during file indexing. I've eliminated other sessions and this is the only time it crashes.
Looking at the x1.log, I see the following exceptions prior to every crash:

19 Dec 2014 14:25:06,386 [8] INFO UpdateManager - Found latest version: 5003az
19 Dec 2014 14:25:06,386 [8] INFO UpdateManager - Checking http://download.x1.com/downloads/pro/50 ... dates.json for updates to plugins.
19 Dec 2014 14:25:06,426 [8] ERROR UpdateManager - Web exception downloading plugin update information. System.Net.WebException: The remote server returned an error: (403) Forbidden.
at X1.Common.Utils.ProxyNegotiatingWebClient.a[a](Func`1 A_0)
at X1.Common.Utils.ProxyNegotiatingWebClient.DownloadString(String address)
at X1.UI.Updater.UpdateManager.DownloadPluginUpgradeInfo(String x1Version)
19 Dec 2014 14:25:06,426 [8] INFO UpdateManager - Current x1 version is the latest and no plugin patches are available
19 Dec 2014 14:26:42,225 [1] ERROR ServiceManager - HandleServiceError: The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state.
Server stack trace:
at System.ServiceModel.Channels.CommunicationObject.ThrowIfDisposedOrNotOpen()
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 X1.UI.X1ServiceMain.IX1Service.UpdateCacheValues(String[] keys, String[] values)
at X1.UI.WCF.ServiceManager.SetValueByName(String name, String val)
19 Dec 2014 14:26:45,897 [1] INFO ServiceManager - HandleServiceError - restartOnExit=False
19 Dec 2014 14:26:45,963 [1] ERROR SearchSessionManager - Exception caught and ignored in DestroySearchSession
System.ServiceModel.CommunicationObjectFaultedException: The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state.

Server stack trace:
at System.ServiceModel.Channels.CommunicationObject.ThrowIfDisposedOrNotOpen()
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 X1.UI.X1SearchManager.IX1SearchManager.DestroySearchSession(Int32 sessionID)
at X1.UI.WCF.SearchSessionManager.DestroySearchSession(Int32 sessionID)

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