How many targets was the job executed against?
What is the Job Parallelism set to?
How many Job Application Servers are there?
When you resolved this (for another customer) back in February "your suggestion to limit remediation jobs in parallel worked as a charm" :-)
Running just against one target.
4 job application servers we have.
is the agent running when you get that error ? where's the rscd log ? and the rscd log from the repo helper.