This official document is a very good reference, just that now there are many more fuzzers.
https://f4pga.readthedocs.io/projects/prjxray/en/latest/db_dev_process/newpart.html
Error might be confusing (as when error occurs, all “current running jobs” will be stopped, making other fuzzers in half-done state — but no worries, other fuzzers will start from scratch if being run again). Troubleshooting on single thread is better.