When Final Cut Server is converting a file from one format to another, importing files, etc. a job is added to the queue. To view the status of these jobs, click on the menu button and click on Search All Jobs.
You will see the last jobs run, which can be a lot of jobs in some instances. Now click on the disclosure triangle next to the magnifying glass and you will see a list of search parameters. You can then switch Status to Equals and enter FAIL in the status box as seen here.
If you click on the search button you will only see failed jobs. You can also search by any of the other fields listed here. One that I use a lot when doing initial installations is to switch the status field to Not Equals and use the word DONE. This will only show me jobs that are Failed or In Progress. Further, the search fields in Final Cut Server are such that I could also constrain my search to a specified time to see jobs that have Failed in that time frame.
While Final Cut Server is processing a job, the green bar will move showing you how far along the job is. If you double-click on a job it will show you statistics on the job (like progress) and you can click on the Logs tab to see why the job failed.