Fixed: Broken tasks getting stuck in queue

src/NzbDrone.Core/Messaging/Commands/CommandExecutor.cs

@@ -66,14 +66,16 @@ namespace NzbDrone.Core.Messaging.Commands
 
         private void ExecuteCommand<TCommand>(TCommand command, CommandModel commandModel)
             where TCommand : Command
+        {
+            IExecute<TCommand> handler = null;
+
+            try
             {
                 var handlerContract = typeof(IExecute<>).MakeGenericType(command.GetType());
-            var handler = (IExecute<TCommand>)_serviceFactory.Build(handlerContract);
+                handler = (IExecute<TCommand>)_serviceFactory.Build(handlerContract);
 
                 _logger.Trace("{0} -> {1}", command.GetType().Name, handler.GetType().Name);
 
-            try
-            {
                 _commandQueueManager.Start(commandModel);
                 BroadcastCommandUpdate(commandModel);
 
@@ -108,10 +110,13 @@ namespace NzbDrone.Core.Messaging.Commands
                 {
                     ProgressMessageContext.CommandModel = null;
                 }
-            }
 
+                if (handler != null)
+                {
                     _logger.Trace("{0} <- {1} [{2}]", command.GetType().Name, handler.GetType().Name, commandModel.Duration.ToString());
                 }
+            }
+        }
 
         private void BroadcastCommandUpdate(CommandModel command)
         {