If your job starts producing errors instead of frames, you’ll notice it will change from green to brown, then eventually to red. This change happens as the error count column is increases from zero to the configurable maximum number of errors. These errors have reports that can be viewed in the "Job Reports" panel.
To open the "Job Reports" panel go to "View" menu, or right-click the job or task and select "View Job Reports". Here you will find all the reports generated for a job including the error reports which will be red. You can filter and sort the reports by features such as the machine which ran the task or the render time to help find what you are looking for.
If you’re ever unsure of what an error means, please feel free to attach the log to a new ticket to Support and we'll take a look! To save a job report, just right click one or more jobs and pick "Save". While you wait for a response, it will be worth reading the log starting from the bottom and working to the top. More information that can help you resolve your problem can be found in our troubleshooting guide.
If you think the error might be related to the submission settings you can also send us an archive of the job for us to look at. You can create that by right clicking on a non-rendering job in the Monitor and choosing 'Archive Job'. That will bundle up the job reports, the submitted scene data, as well as the settings used to create the job. It will be worth checking the contents of the zip file to make sure you're not sending sensitive scene data.