Service broker stopped working

Hi,

I'm new to Service Broker. Our existing Service Broker suddenly stops working and I can't figure out why.

When I try to enable Service Broker (which is already enabled) I get this in SQL error log:

An error occurred in the service broker manager 
Error: 3602, State: 25.

Also tried creating new message queues. I am able to see the created queues undersys.service_queues and sys.objects but not in sys.dm_broker_queue_monitors.