Background jobs return 404 or not at all because they aren't delegating properly. This ticket addresses that.
This error started appearing after the patch was deployed. Related?
The error turns out to be more than just logging. The error occurs when SSP attempts to execute a task in the job_queue. Email, watch and changes program_status job fail to run and remain in the 'queued' status in the job_queue table.
See comments related to job_queue job failure
I've tried reproducing both on Linux with Postgres and Windows with SQL Server and I'm unable to reproduce. We'll discuss more via email/chat.
The problem was reproduced by initiating bulk jobs and patch committed to correct it.