Issue 1: Include External Files
If your workbook runs off of a local extract, you will have to publish the extract to the server as well in order to have any data. However, I was unaware that this applied to Custom Geocoding as well. My workbook did not run off of a local extract, so I didn't see the need to include any external files. I was wrong. When I attempted to look at the workbook on the server, I would get an error and none of the graphs would display. It turns out that "Include External Files" applies to local extracts as well as custom geocoding. I haven't found a case where it was disadvantageous to check this box. If you have, feel free to comment.
Issue 2: Packaging the Workbook
I had a worksheet with no external files that ran perfectly on my local machine. However, when I published it to the Tableau Server, I would get an error saying "Field is invalid" and nothing would display. Through trial and error, I found that the field was a necessary Date field. Finally, I discovered that packaging the workbook would fix the problem. I'm still curious as to why this is. Needless to say, I always package my workbooks before I publish.
Issue 3: "Ghost" Columns
Once, I ran into an issue where I had an invalid field that was not appearing in Tableau Desktop, yet was causing an error on Tableau Server. The error said something like "[Calculation_280932] is invalid." I found a solution on a forum that I've forgotten how to find (Sorry to whoever wrote that, I wish I could credit you). First, make sure there are no hidden fields in Tableau Desktop. If you open the Tableau Workbook using Notepad, or some other rudimentary text-editing software, you can look at the XML code defining the workbook. If you search for "hidden", you may find that there is a column that is labeled as hidden, even though it wasn't visible to Tableau Desktop. If you delete this column, everywhere else it is called, and any syntax it leaves behind, you will have effectively eliminated it from the workbook. Now, you can publish the workbook with no issues. I HIGHLY recommend saving a copy of the workbook before you edit the XML code. It would be very unfortunate if you broke your workbook with no way of repairing it.
I hope you found this informative. If you have encountered any publishing issues and would like to share, feel free to comment. Thanks for reading.