Queue Not Found Error

I am getting the warning "Job queue XXX not found. The job will be run using the [default] queue." periodically. The queue still exist but the only way to get it to use it again is to reboot the server. When this happens I also find jobs slowly stop running, for example, will not start even though the semaphore file exist. I am using v3.4.20. Is this a known issue? How can I resolve it?

Thanks.

Please turn on the tracing in the Tools/Options menu; Log tab. Trace enabled option and then restart the scheduler. This will produce additional messages in the job log that could lead to the root cause of the job queuing issue.

Please let us know what you get there.