MessageQueue.Exists(QueueName) returns false but it exists

Question

The problem I'm having is with this code:

if (!MessageQueue.Exists(QueueName))
{
    MessageQueue.Create(QueueName, true);
}

It will check if a queue exists; if it doesn't I want it to create the queue. This code has been working and hasn't changed for a few months. Today I started receiving this error:

[MessageQueueException (0x80004005): A queue with the same path name already exists.] System.Messaging.MessageQueue.Create(String path, Boolean transactional) +239478

The queues are local and if I delete the specific queue it will work once. After the queue is created it starts to fail again with the same error message.

Answer 1

It looks like the issue may be because of the Network Load Balancing (NLB) configuration. I was unaware of a change that recently put the machine in a NLB environment. The configuration we are using is an unsupported one.

More information is in How Message Queuing can function over Network Load Balancing (NLB).